The Ultimate Cheesy Brussel Sprout Casserole

Let’s be real for a second. If you grew up thinking Brussels sprouts were those sad, mushy, bitter little green things forced upon you at holiday dinners, you aren’t alone. But I’m here to tell you that this cheesy Brussel sprout casserole is going to completely change your mind. It did for my family! I’ve actually converted quite a few sprout-haters with this exact dish, and honestly, it has become one of my most requested sides year after year.

Imagine tender, perfectly roasted sprouts swimming in a rich, garlicky, creamy cheese sauce, all baked until golden and bubbly. It is pure comfort food that just so happens to be low-carb and gluten-free. Whether you are throwing together a quick weeknight dinner or planning your massive Thanksgiving or Christmas menu, this dish fits right in. Grab a cup of coffee (or a glass of wine) and let me walk you through how to make my absolute favorite veggie side. You’re going to love it!

What Is A Brussel Sprout Casserole?

If you haven’t experienced the magic of this dish yet, you are in for a serious treat. At its core, a Brussel sprout casserole is a baked vegetable side dish that takes the humble Brussels sprout and elevates it to steakhouse-level decadence. Instead of just boiling or steaming them (please don’t do that!), we give the sprouts a quick pre-roast in the oven. This crucial step brings out their natural sweetness and ensures they get perfectly tender.

Then, they get folded into a luxurious sauce made from heavy cream, minced garlic, Italian seasoning, and a whole lot of freshly shredded mozzarella and parmesan cheese. The whole mixture gets transferred to a baking dish, topped with even more cheese, and baked until the edges are beautifully browned and the center is bubbling. It is basically the sophisticated, slightly more grown-up cousin to macaroni and cheese. It hits all those cozy, comforting notes while sneaking in a healthy dose of green vegetables.

How to Make Brussel Sprout Casserole

Quick Overview

Making this glorious, cheesy side dish is a breeze, even if you aren’t super confident in the kitchen. The process comes down to three main phases: prepping and pre-roasting your sprouts, mixing up that luscious, creamy cheese sauce, and baking it all together until it reaches gooey perfection. By pre-roasting the vegetables first, we lock in their flavor and make sure they soften beautifully before they hit the cream sauce. After that, it is just a matter of stirring everything together in one big bowl, pouring it into your favorite cast iron skillet or baking dish, and letting the oven do the rest of the heavy lifting.

Ingredients

• Brussels sprouts: 3 cups, fresh. Make sure to cut the bottoms off and slice them in half. If they are huge, quarter them so everything cooks evenly.
• Olive oil: 1 tablespoon for roasting the sprouts.
• Salt and black pepper: 1 teaspoon each, divided. Half for roasting, half for the sauce.
• Heavy cream: 1 cup. This gives us that ultra-rich texture. (Half-and-half works in a pinch!)
• Garlic: 4 cloves, freshly minced for the best savory punch.
• Italian seasoning: 1 tablespoon to add incredible herby flavor.
• Parmesan cheese: 1 cup freshly shredded, divided.
• Mozzarella cheese: 1 ½ cups shredded, divided for the sauce and the gooey topping.

Step-by-Step Instructions

Step 1: Preheat & Prep Pan

Start by preheating your oven to 400°F. Grab a 12-inch round cast iron skillet or a 9×9 small casserole dish and lightly butter the inside so nothing sticks. Set it aside for now.

Step 2: Pre-Roast the Sprouts

Toss your prepared Brussels sprouts with the olive oil, and arrange them in a single layer on a parchment-lined baking sheet. Sprinkle them with 1/2 teaspoon of salt and 1/2 teaspoon of pepper. Roast them in the hot oven for about 12 minutes. Once they are done, pull them out and let them cool for just 5 minutes.

Step 3: Mix the Cheesy Sauce

While the sprouts are cooling, grab a large mixing bowl. Combine your heavy cream, minced garlic, Italian seasoning, 3/4 cup of the parmesan cheese, 1 cup of the mozzarella cheese, and the remaining 1/2 teaspoon of salt and pepper. Stir it all up until well combined.

Step 4: Combine and Top

Gently fold your pre-roasted sprouts into the creamy cheese mixture until they are completely coated. Pour everything into your prepared skillet or baking dish. Finally, sprinkle the remaining 1/4 cup of parmesan and 1/2 cup of mozzarella evenly over the top.

Step 5: Bake to Perfection

Bake the casserole uncovered for 25 to 30 minutes. You are looking for a beautifully browned, bubbly masterpiece. Let it rest for about 5 to 10 minutes before serving so the sauce can thicken up slightly. Enjoy!

What to Serve It With

Because this Brussel sprout casserole is so rich and flavorful, it pairs wonderfully with just about any protein you can think of. For a cozy weeknight dinner, I absolutely love serving it alongside a simple baked chicken breast, a classic homemade meatloaf, or even some juicy grilled pork chops. The creamy sauce acts almost like a gravy, complementing the meat perfectly.

If you are making this for a holiday feast, it truly shines next to a beautifully roasted Thanksgiving turkey or a sweet, sticky slow-cooker ham. Honestly, I have even been known to scoop a big portion of this next to a perfectly seared steak for an at-home “steakhouse” date night. You really can’t go wrong!

Top Tips for Perfecting Your Brussel Sprout Casserole

Over the years, I have made this recipe dozens of times, and I’ve picked up a few handy tricks to make sure it comes out flawless every single time:

• Dry your sprouts well: After rinsing your fresh Brussels sprouts, pat them completely dry with a kitchen towel before roasting. Any leftover water will steam them instead of roasting them, which can make your casserole watery.
• Shred your own cheese: I know the pre-bagged stuff is convenient, but taking a few extra minutes to shred your own block of mozzarella and parmesan makes a world of difference. Pre-shredded cheese is coated in anti-caking agents that prevent it from melting smoothly into the cream.
• Watch the broiler: If you want an extra crispy, browned top, you can pop the finished casserole under the broiler for 30 to 60 seconds. Just don’t walk away! It can go from golden to burnt in the blink of an eye.
• Add a crunchy topping: For amazing texture, mix 1/2 cup of panko breadcrumbs with a tablespoon of melted butter and sprinkle it over the cheese layer before baking.
• Toss in some extras: Feel free to customize this! Crispy cooked bacon bits, diced pancetta, or even some caramelized onions stirred into the mixture before baking are incredible additions.

Storing and Reheating Tips

If you happen to have leftovers (which is a rare occurrence in my house!), you can easily save them for later. Transfer the cooled casserole into an airtight container and store it in the refrigerator for up to 4 days. I strongly advise against freezing this dish, as the heavy cream and cheese sauce will separate and become grainy once thawed.

When you are ready to reheat, you have a couple of options. For a quick lunch, you can pop individual portions into the microwave for 30 to 45 seconds until warmed through. If you are reheating a larger amount, place it in an oven-safe dish and warm it in a 350°F oven for 10 to 15 minutes. If the sauce seems a little thick or dry after sitting in the fridge, just stir in a tiny splash of heavy cream before reheating to bring it back to its original creamy glory.

Frequently Asked Questions

Final Thoughts

I really hope this rich and cheesy Brussel sprout casserole brings as much joy to your dinner table as it does to ours. It is one of those rare, magical recipes that manages to feel incredibly indulgent while still getting a healthy serving of veggies onto everyone’s plate. Whether you are trying to impress your mother-in-law at Thanksgiving or just want a cozy, comforting side dish for a chilly Tuesday night, this recipe has your back.

If you decide to give it a try, I would love to hear how it turns out for you! Don’t be afraid to make it your own by adding some crispy bacon or playing around with your favorite cheeses. Happy cooking, friends, and enjoy every single creamy, garlicky bite!

Cheesy Brussel Sprout Casserole

This easy Brussel Sprout Casserole with a creamy, garlicky sauce is topped with gooey cheese to please even the pickiest of eaters! Bonus: It's low-carb and gluten-free!

Prep : 10 Total : 25 minutes

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Ingredients

  

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Main Ingredients

• 3 cups Brussels sprouts bottoms removed and halved
• 1 tablespoon oil
• 1 teaspoon salt divided
• 1 teaspoon freshly cracked black pepper divided
• 1 cup heavy cream
• 4 cloves garlic minced
• 1 tablespoon Italian seasoning
• 1 cup shredded parmesan cheese or asiago, divided
• 1.5 cups shredded mozzarella cheese divided

Instructions

 

Preparation Steps

• Preheat oven to 400°F. Butter a 12-inch round cast iron skillet or a small casserole dish (like a 9x9), set aside.
• Toss Brussels sprouts with oil and arrange on a baking sheet lined with parchment paper. Sprinkle 0.5 tsp salt and 0.5 tsp pepper over the sprouts. Roast in the oven for 12 minutes. Remove from the oven and set aside to cool for 5 minutes.
• In a large bowl, combine the heavy cream, garlic, Italian seasoning, 0.75 cup parmesan cheese, 1 cup mozzarella cheese, and renaming 0.5 tsp salt and 0.5 tsp pepper.
• Fold in the Brussels sprouts and pour mixture into the prepared skillet/casserole dish. Sprinkle the remaining cheeses (0.25 teaspoon parmesan and 0.5 cup mozzarella) over the top of the casserole.
• Bake for 25 to 30 minutes, until bubbly and edges are browned. Let rest for 5 minutes and then serve immediately!

Notes

Make ahead: Assemble the casserole up to 24 hours in advance, cover tightly, and refrigerate. When ready to bake, let casserole sit at room temperature for 15 minutes uncovered, then bake as directed.