Easy Brussels Sprouts Casserole Recipe
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Brussels Sprouts Casserole is the perfect mix of crispy, roasted sprouts, and a creamy, savory sauce; all finished with crunchy fried onions. Whether you’re a fan of Brussels sprouts or looking for a way to win over skeptics, this dish is an easy win.
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Deliciously tasty, super easy to make, and very budget-friendly, this is why I love making this casserole. It’s great for the holidays, Friendsgiving, and potlucks, and it’s a real crowd-pleaser, even for those who don’t think they like Brussels sprouts! Give it a try; I think it’ll become a favorite.
Ingredients You’ll Need
You’ll need all the ingredients shown in the photograph below.
How to Make Brussels Sprouts Casserole with Step-By-Step Instructions
A complete printable recipe and the measurements in both US customary and metric are available in the recipe card below.
Follow my easy steps, and you’ll be enjoying this casserole in no time!
Prep and Roast the Brussels Sprouts
Preheat your oven to 180ºC (350°F).
Trim and cut the Brussels sprouts in half, then place them in a casserole dish. Drizzle with olive oil, sprinkle with salt and pepper, and give them a good toss.
Roast in the oven for 20 minutes until they start to brown.
Prepare the Sauce
In a small saucepan, melt the butter over medium heat. Add the finely chopped onions and garlic powder, stirring occasionally until the onions are soft and translucent, about 5-7 minutes.
Stir in the flour to form a thick paste. Slowly pour in the milk, whisking continuously to avoid lumps. Cook until the sauce thickens, stirring frequently.
Combine and Bake Again
Once the Brussels sprouts are out of the oven, pour the sauce evenly over them. Return the casserole to the oven and bake for another 10 minutes, or until the top turns golden and bubbly.
Garnish and Serve
When the casserole is done baking, sprinkle with fresh parsley and top with crispy fried onions before serving.
Equipment
Ingredients
- 4 cups brussels sprouts trimmed and cut in half (fresh)
- 1 tablespoon olive oil
- Salt and pepper
- 1 tablespoon butter
- ¼ cup onions finely chopped
- ¼ teaspoon garlic powder
- 2 tablespoons all-purpose flour
- 1 cup milk
Toppings:
- Fresh parsley
- Fried onions
Video
Instructions
- Preheat the oven to 180ºC (350°F).
- Trim the Brussels sprouts and cut them in half. Place them in a casserole dish, drizzle with olive oil, and season with salt and pepper. Toss everything to coat evenly. Bake in the oven for about 20 minutes, until the Brussels sprouts start to brown and soften.4 cups brussels sprouts, 1 tablespoon olive oil, Salt and pepper
- In a small saucepan, melt the butter and add the onions and garlic powder. Cook for 5-7 minutes. Add the While the Brussels sprouts are roasting, melt the butter in a small saucepan over medium heat. Add the chopped onions and garlic powder, cooking for about 5-7 minutes until the onions are softened and translucent.1 tablespoon butter, ¼ cup onions, ¼ teaspoon garlic powder
- Stir in the flour to create a paste, then slowly add the milk while stirring constantly to avoid lumps. Continue stirring until the sauce thickens.flour and mix until a thick paste is formed. Add the milk and mix until well combined, stir frequently until it thickens.2 tablespoons all-purpose flour, 1 cup milk
- Take the Brussels sprouts out of the oven and pour the sauce over them, spreading it evenly. Return the casserole to the oven and bake for an additional 10 minutes, until the top is golden and bubbly.
- Once baked, garnish the casserole with fresh parsley and crispy fried onions. Serve hot.Fresh parsley, Fried onions
Notes
- Perfect Roasting: Make sure your Brussels sprouts are in a single layer in the dish so they roast evenly.
- Creamy Sauce: If your sauce ends up too thick, you can easily thin it out with an extra splash of milk. Stir the sauce well to ensure it remains smooth, and avoid any lumps by adding the milk slowly.
- Avoid Overcooking: Keep a close eye on the casserole during the second bake. Overcooked Brussels sprouts can lose their firm texture, so remove the dish from the oven as soon as it’s golden and bubbly to preserve a bit of crunch.
- Fried Onion Topping: For maximum crunch, add the fried onions just before serving. This prevents them from softening under the heat of the casserole, ensuring that you get that crispy bite with every forkful.
- Prep Ahead: You can roast the Brussels sprouts a day in advance and store them in the fridge.
- Make it Gluten-Free: Swap out the all-purpose flour with your favorite gluten-free flour blend to make this casserole gluten-friendly.
Nutrition
Recipe Notes and Expert Tips
Here are some of my tips to ensure your casserole turns out perfect every time:
- Perfect Roasting: Make sure your Brussels sprouts are in a single layer in the dish so they roast evenly.
- Creamy Sauce: If your sauce ends up too thick, you can easily thin it out with an extra splash of milk. Stir the sauce well to ensure it remains smooth, and avoid any lumps by adding the milk slowly.
- Avoid Overcooking: Keep a close eye on the casserole during the second bake. Overcooked Brussels sprouts can lose their firm texture, so remove the dish from the oven as soon as it’s golden and bubbly to preserve a bit of crunch.
- Fried Onion Topping: For maximum crunch, add the fried onions just before serving. This prevents them from softening under the heat of the casserole, ensuring that you get that crispy bite with every forkful.
- Prep Ahead: You can roast the Brussels sprouts a day in advance and store them in the fridge.
- Make it Gluten-Free: Swap out the all-purpose flour with your favorite gluten-free flour blend to make this casserole gluten-friendly.
How to Store Leftover Brussels Sprouts Casserole
To store leftover Brussels Sprouts Casserole, allow it to cool completely before transferring it to an airtight container.
You can refrigerate it for up to 3 days. When reheating, bake in a preheated oven at 180ºC (350°F) until warmed through to maintain the casserole’s crispiness.
This casserole is not ideal for freezing, as the Brussels sprouts can become mushy upon thawing, and the sauce may separate. For best results, enjoy the leftovers within a few days for the freshest taste and texture.
What to Serve With Brussels Sprouts Casserole
This casserole is perfect as a side to a delicious Nut Roast, Mushroom Wellington, or Vegan Ham.
Add a little Cornbread, Scalloped Potatoes, or Honey Roasted Carrots, and you’ve got yourself a delicious meal.
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