Savory Brussels Sprouts and Mushroom Bake

This Brussel Sprout Casserole is a truly spectacular side dish, crafted with the freshest brussels sprouts and a luscious homemade cream of mushroom soup. It’s a flavor explosion, while also being remarkably healthy, fully vegetarian, and completely gluten-free!

Forget complicated recipes; this from-scratch dish is surprisingly easy to prepare, requiring just 15 minutes of active prep time. Its versatility makes it the perfect accompaniment for grand holiday feasts or a delightful addition to simple weeknight dinners!

As the holiday season draws near, the excitement builds, especially for those treasured Thanksgiving gatherings. It’s a time for warmth, family, and, of course, unforgettable food. This year, I’m thrilled to share a recipe that promises to elevate your festive spread and impress even the most discerning palates: a modern take on a classic holiday staple.

This exquisite Brussels Sprout Casserole was born from a desire to reinvent the ubiquitous Green Bean Casserole. You know the one – a staple on many holiday tables, traditionally featuring canned green beans, condensed cream of mushroom soup straight from a can, and a generous topping of crispy fried onions. While undeniably a part of culinary nostalgia for many, its health credentials and fresh flavor profile often leave something to be desired.

My aim was to create a dish that captured the comforting creaminess and hearty appeal of the original, but with a vibrant, fresh, and wholesome twist. Instead of relying on canned goods, this recipe champions fresh produce and homemade goodness. We swap out the often mushy canned green beans for crisp, nutrient-rich fresh Brussels sprouts, and craft our own rich, velvety cream of mushroom soup using earthy portobello or baby bella mushrooms.

One of my favorite culinary secrets for creating this healthy, vegetarian, and gluten-free masterpiece lies in the thickener. Instead of traditional flour, which contains gluten, I use cornstarch. This is a brilliant gluten-free cooking tip that ensures your sauce is perfectly smooth and thick without compromising on dietary needs. Cornstarch provides an excellent, neutral-tasting thickening agent, making this casserole accessible to more people without sacrificing flavor or texture.

The result is nothing short of extraordinary: an incredibly flavorful, luxuriously creamy, rich, and undeniably decadent Brussels sprout casserole. Since its inception in 2014, this recipe has been a consistent crowd-pleaser at holidays and special occasions, earning rave reviews and becoming a firm family favorite. It offers all the comfort of a traditional casserole but with a gourmet touch and the added benefits of being vegetarian and gluten-free.

While this casserole shines as a centerpiece on your Thanksgiving or Christmas table, its ease of preparation means it’s also perfect for any time of year. Imagine pairing it with a savory Bacon Wrapped Meatloaf or a comforting Chicken Pot Pie for a delicious, hearty meal on a regular weeknight. Its versatility truly knows no bounds, making it a valuable addition to your recipe repertoire.

Whether you’re hosting a grand celebration or simply looking for an impressive yet easy-to-make side dish, this Brussels Sprout Casserole with homemade mushroom soup will undoubtedly steal the show. It’s a testament to how fresh ingredients and thoughtful preparation can transform a classic into a modern, healthier, and utterly delicious creation.

Table of Contents

• Ingredients Overview
• Detailed Step-by-Step Instructions
• Frequently Asked Questions
• Transforming into a Main Dish
• Serving Suggestions
• More Brussels Sprouts Delights

Essential Ingredients for Your Brussel Sprout Casserole

Crafting this exceptional Brussels sprout casserole begins with selecting high-quality, fresh ingredients. Each component plays a crucial role in building the layers of flavor and achieving that perfectly creamy texture. Here’s what you’ll need:

• Unsalted Butter: The foundation of our rich mushroom soup, unsalted butter allows you to control the overall sodium content of the dish while imparting a delicious, savory base.
• Baby Bella or Portobello Mushrooms: These provide the deep, umami flavor that makes our homemade cream of mushroom soup so extraordinary. Baby bella mushrooms are simply smaller, younger portobello mushrooms, and both varieties work wonderfully. Look for firm, fresh mushrooms in the produce section of your grocery store.
• Salt: Essential for seasoning the mushrooms and balancing the overall flavors of the casserole. We recommend kosher salt for its pure taste.
• Black Pepper: Freshly ground black pepper adds a pungent warmth that complements the earthiness of the mushrooms and sprouts.
• Fresh Thyme: This aromatic herb brings a delicate, earthy, and slightly floral note to the mushroom soup, enhancing its gourmet appeal. Fresh herbs always make a noticeable difference in flavor.
• Garlic Cloves: Minced fresh garlic is indispensable for its pungent, savory depth, which is crucial for a truly flavorful mushroom soup.
• Ground Nutmeg: A pinch of nutmeg adds a subtle, warm, and slightly sweet spice that beautifully rounds out the flavors of creamy dishes, particularly those featuring mushrooms and dairy.
• Cornstarch: Our secret weapon for a gluten-free and perfectly thickened cream sauce. Cornstarch is a fantastic alternative to flour, creating a smooth, glossy sauce without any grainy texture.
• Vegetable Broth: This provides the liquid base for our homemade mushroom soup. Using vegetable broth keeps the dish entirely vegetarian. However, if you’re not adhering to a vegetarian diet, feel free to substitute with chicken or turkey broth for a slightly different flavor profile.
• Half-and-Half: A blend of half milk and half heavy cream, half-and-half delivers a luscious richness to the sauce without being excessively heavy. It’s readily available in the dairy aisle of most supermarkets.
• Fresh Brussels Sprouts: The star of our casserole! Choose firm, bright green sprouts without any yellowing or soft spots. Their slightly bitter, nutty flavor softens and sweetens beautifully during baking, making them the perfect complement to the creamy mushroom sauce. We’ll be trimming and halving them to ensure they cook evenly and absorb all the delicious flavors.
• Parmesan Cheese: A generous topping of grated Parmesan cheese adds a salty, savory, and nutty crust to the casserole, providing an irresistible finish.

You’ll find the precise measurements for all these ingredients conveniently listed in the comprehensive recipe card located at the bottom of this article.

Detailed Step-by-Step Instructions for Your Perfect Brussel Sprout Casserole

Creating this decadent Brussels sprout casserole is simpler than you might imagine, with just a few key steps that ensure maximum flavor and optimal texture. Follow these instructions carefully to achieve a truly impressive side dish:

1. Prepare Your Oven: Begin by preheating your oven to 350°F (175°C). This ensures it’s ready when your casserole is assembled, allowing for immediate and even baking.
2. Sauté the Mushrooms: In a large, sturdy skillet, melt the unsalted butter over medium-high heat. Once the butter is bubbling, add your diced portobello or baby bella mushrooms, along with the salt, black pepper, and fresh thyme. Cook the mushrooms for 5-6 minutes, stirring occasionally, until they release their moisture, soften, and begin to turn golden brown. This step is crucial for developing deep, earthy flavor.
3. Infuse with Aromatics: Add the minced garlic and a quarter teaspoon of ground nutmeg to the skillet with the mushrooms. Continue to cook for another 2-3 minutes, stirring constantly, until the garlic becomes fragrant. Be careful not to burn the garlic, as this can make it bitter.
4. Create the Roux Base: Evenly sprinkle the cornstarch over the cooked mushrooms in the skillet. Stir continuously for about 1 minute, ensuring the cornstarch coats the mushrooms thoroughly. This helps create a smooth base for your sauce.
5. Build the Mushroom Soup: Gradually pour the vegetable broth into the skillet, stirring constantly to prevent lumps from forming. Bring the mixture to a gentle simmer and cook for 1-2 minutes, allowing the sauce to begin thickening.
6. Add the Creaminess: Reduce the heat to medium-low. Pour the half-and-half into the skillet, stirring well to fully incorporate it with the mushroom mixture. Continue to simmer the sauce gently for 6-8 minutes, stirring periodically, until it reaches a rich, creamy consistency that coats the back of a spoon. Taste and adjust seasoning if necessary.
7. Prepare the Brussels Sprouts: While your mushroom soup simmers, prepare your fresh Brussels sprouts. Trim off the tough ends and remove any loose or discolored outer leaves. For larger sprouts, quarter them; for smaller ones, simply halve them. This ensures they cook thoroughly and absorb the sauce beautifully.
8. Assemble the Casserole: Place the prepared Brussels sprouts evenly into a 9-inch x 12-inch oven-safe baking dish or a casserole dish of similar capacity.
9. Combine and Coat: Carefully pour the warm, homemade cream of mushroom soup over the Brussels sprouts in the baking dish. Gently toss the sprouts with the soup using a spoon or spatula, ensuring every sprout is thoroughly coated in the luxurious sauce.
10. Top with Cheese: Sprinkle the grated Parmesan cheese evenly over the top of the coated Brussels sprouts. This will create a delicious, golden-brown crust during baking.
11. Bake to Perfection: Place the uncovered casserole dish into your preheated 350°F (175°C) oven. Bake for approximately 40 minutes, or until the Brussels sprouts are tender when pierced with a fork, the sauce is bubbly, and the cheese topping is golden brown and irresistible.

Once baked, remove the casserole from the oven and let it rest for a few minutes before serving. This allows the flavors to meld and the sauce to set slightly. Get ready to enjoy a truly spectacular side dish!

Frequently Asked Questions About This Brussel Sprout Casserole

To help you perfect this delicious Brussels Sprout Casserole, here are answers to some common questions:

• Do I need to boil or blanch the Brussels sprouts before adding them to this casserole? Absolutely not! One of the beauties of this recipe is its simplicity. The fresh Brussels sprouts will cook to tender perfection directly in the oven, absorbing all the wonderful flavors of the creamy mushroom soup. There’s no need for any pre-cooking steps like boiling or blanching.
• How many people does this recipe serve? This recipe, as written, is perfectly sized to serve 4-6 people as a generous side dish. It’s ideal for a smaller family gathering or a cozy dinner. If you’re planning to serve a larger crowd, especially for a holiday feast, it’s very easy to scale up. Simply double the recipe for 8-12 servings, or even triple it for 12-18 servings. When adjusting, remember to use a larger baking dish to accommodate the increased volume.
• How long will leftover Brussels sprout casserole last in the fridge? Properly stored in an airtight container, any leftover Brussels sprout casserole will remain fresh and delicious in the refrigerator for up to 5 days. This makes it a great make-ahead option or a wonderful dish for meal prepping.
• What’s the best way to reheat the casserole? Reheating is straightforward and can be done either in the oven or microwave, depending on your preference and time constraints.
  • Oven Reheating: For best results, place the desired portion of casserole back into an oven-safe dish. To prevent drying out, cover it loosely with aluminum foil. Reheat in an oven preheated to 350°F (175°C) for 10-15 minutes, or until it’s heated through to your liking. The foil helps keep the casserole moist.
  • Microwave Reheating: For a quicker option, place a single serving of the casserole on a microwave-safe plate. Heat on high for approximately 2 minutes, or until thoroughly warmed. Stir halfway through for even heating.
• Can I use a different type of cheese for the topping? Absolutely! While Parmesan cheese offers a delightful salty, nutty crust, this casserole is quite forgiving with cheese choices. Gruyere cheese would lend a sophisticated, slightly sweeter nuttiness and melt beautifully. Sharp cheddar cheese would provide a bolder, tangier flavor that many find appealing. Feel free to experiment with your favorite melting cheeses to customize the taste.
• Can I make this recipe vegan? Yes, with a simple substitution! To transform this into a vegan Brussels sprout casserole, you’ll need to adapt the cream of mushroom soup and omit the Parmesan cheese. We recommend using a dedicated Vegan Cream of Mushroom Soup recipe as your base. Prepare that vegan soup, then pour it over the Brussels sprouts in your baking dish, just as instructed. Skip the Parmesan cheese topping (or use a vegan Parmesan substitute if you prefer). Then, bake as directed until the sprouts are tender and the casserole is bubbly.

Transform Your Brussels Sprout Casserole into a Hearty Main Dish

While this Brussels sprout casserole shines as a side dish, it’s so irresistibly good that you might want to make it the star of your meal! With a few simple additions, you can easily transform this flavorful side into a complete, satisfying main course. Here’s how to incorporate your favorite proteins:

• Add Chicken for a Lean Protein Boost: If you’re looking to add tender chicken, cube one pound of boneless, skinless chicken breasts. In a bowl, toss the chicken cubes with 1 tablespoon of olive oil, ½ teaspoon of salt, ½ teaspoon of black pepper, and ½ teaspoon of fresh thyme leaves. Heat a large skillet over medium-high heat (the same one you’ll use for the mushrooms if you like!). Add the seasoned chicken and cook for about 5 minutes, flipping the pieces regularly until they are nicely seared and cooked through. Remove the chicken from the skillet and set it aside. Proceed with making the homemade cream of mushroom soup as directed in the recipe. Once the soup is ready, combine the prepped Brussels sprouts and the seared chicken pieces in your baking dish. Pour the mushroom soup over both the sprouts and chicken, tossing gently to ensure everything is well coated. Finish with the grated Parmesan cheese and bake as instructed.
• Incorporate Bacon for Smoky Depth: For those who love a smoky, savory kick, bacon is an excellent addition. To start, omit the butter from the original recipe. Instead, chop 4-6 slices of thick-cut bacon into small pieces and add them to a large skillet over medium-high heat. Cook the bacon for 5-6 minutes, or until it’s wonderfully crispy. Use a slotted spoon to remove the cooked bacon bits and place them on a paper towel-lined plate to drain, reserving the flavorful bacon grease in the skillet. Now, use this rendered bacon grease to sauté your mushrooms and prepare the mushroom soup, following the recipe instructions precisely. Continue the rest of the casserole assembly as directed. After the casserole has finished baking, stir the crispy cooked bacon bits into the hot casserole just before serving. This ensures they retain their crunch and distribute their smoky flavor evenly.
• Boost with Savory Sausage: Adding sausage is another fantastic way to turn this casserole into a full meal. For this option, we recommend pre-cooking the sausage separately. Place 3-4 raw sausage links (such as Italian, chicken, or turkey sausage) on a small baking sheet. During the last 20 minutes of the casserole’s baking time, add the baking sheet of sausages to the oven, allowing them to cook alongside the casserole. Once the casserole is done, remove both the casserole and the sausages from the oven. Slice the cooked sausages into rounds or chunks, then gently toss them into the baked Brussels sprout casserole before serving. The savory notes of the sausage will perfectly complement the creamy sprouts and mushrooms.

By incorporating any of these proteins, you can easily transform this delightful side dish into a satisfying and complete meal, perfect for any occasion!

Perfect Pairings: What to Serve with Your Brussel Sprout Casserole

This creamy Brussels Sprout Casserole is incredibly versatile, making it an ideal companion for a wide array of main dishes. While it’s a quintessential side for Thanksgiving, its rich, comforting flavors are equally welcome year-round. Here are some fantastic main course ideas that pair beautifully with this casserole, creating a truly memorable meal:

• The BEST Marinated Sirloin Steak: The robust flavors of a perfectly marinated and cooked sirloin steak find a creamy, earthy balance with this casserole. The richness of the beef is wonderfully complemented by the savory sprouts and mushroom sauce.
• Oven Roasted Turkey Breast: A classic holiday pairing! The tender, herb-crusted turkey breast offers a lean and flavorful counterpoint to the creamy, indulgent casserole. This duo is a staple for any festive gathering.
• French Onion Pot Roast: Imagine the deep, caramelized onion flavors and tender beef of a pot roast alongside the luxurious Brussels sprout casserole. This combination delivers ultimate comfort food, rich and satisfying in every bite.
• Instant Pot Chicken Stroganoff: For a weeknight meal that feels special, pair this quick and flavorful chicken stroganoff with the casserole. The creamy mushroom notes in both dishes will harmonize beautifully, creating a cohesive and delightful dinner.
• Bacon Wrapped Turkey Breast: If you’re looking for an extra layer of savory indulgence, a bacon-wrapped turkey breast is an excellent choice. The crispy bacon and juicy turkey, combined with the creamy casserole, create a symphony of textures and flavors.

No matter what main dish you choose, this Brussels Sprout Casserole is guaranteed to be a hit, adding a touch of gourmet comfort to your table.

More Delightful Brussels Sprouts Recipes to Explore

If you’ve fallen in love with Brussels sprouts as much as we have, you’re in for a treat! This versatile vegetable can be transformed into an incredible array of dishes, from crispy roasted sides to refreshing salads. If you’re a fellow Brussels sprouts enthusiast, you are guaranteed to enjoy these additional recipes that celebrate this fantastic green:

• Roasted Brussels Sprouts with Maple and Apples: A perfect autumnal dish that brings out the natural sweetness of Brussels sprouts with the tartness of apples and the warmth of maple syrup.
• Grilled Brussels Sprouts: For a smoky, charred flavor, grilling Brussels sprouts is an excellent method. They become tender on the inside with deliciously crispy edges.
• Maple Bacon Brussels Sprouts: This popular combination highlights the savory notes of bacon with the sweet glaze of maple syrup, a guaranteed crowd-pleaser.
• Stuffed Acorn Squash with Brussels Sprouts: A beautiful and hearty vegetarian main course or side, featuring roasted squash filled with a flavorful Brussels sprout mixture.
• Brussels Sprout Salad with Dijon Dressing: For a lighter, fresher take, this vibrant salad combines thinly shaved raw Brussels sprouts with a zesty Dijon vinaigrette.

Explore these recipes and discover new ways to enjoy the wonderful flavors and nutritional benefits of Brussels sprouts!