What’s in Brussels Sprouts Au Gratin?

This super easy bacon Brussels sprouts gratin is one of my all-time favorite side dishes. It’s the ultimate way to eat your greens! Who can resist Brussels sprouts when they are tossed in a creamy white sauce, sprinkled with tons of bacon, and topped with loads of white cheddar? I know I can’t!

Brussels Sprouts: The star of the show. Let me tell you, if you think you’re not a fan of them, I’m here to change your mind! Butter + Flour: Create a roux to thicken the sauce. Skim Milk: Forms the base of the sauce. For a creamier sauce, swap the skim milk for whole milk, half-and-half, or heavy cream. Salt + Pepper: Enhance the natural flavor of the sauce. Cheese: Parmesan cheese adds a salty and umami flavor to the sauce, while white cheddar creates that bubbly gratin top! Bacon Crumbles: Add an extra touch of salty and umami flavor!

Pro Tip: Shred your own cheese from a block for the smoothest sauce. Pre-shredded cheese is coated in starches that can cause the sauce to become grainy!

Variations on Au Gratin Brussels Sprouts

Feel free to switch up the cheese. Some other great cheeses include Swiss, fontina, Havarti, gouda, or mozzarella. You can also add 1-2 teaspoons of fresh herbs to the cheese sauce or top your casserole with breadcrumbs of crumbled Ritz crackers. For a vegetarian version, swap out the bacon from slivered almonds.

How to Store and Reheat

Store leftover Brussels sprouts gratin in an airtight container in the refrigerator for up to 5 days. Reheat in a 350°F oven covered with foil for about 20 minutes, or until hot.

How to Freeze

Freeze Brussels sprouts gratin in individual portions in airtight containers for up to 2 weeks. Let thaw overnight in the refrigerator before reheating.

Serving Suggestions

Serve these cheesy Brussels sprouts alongside holiday favorites, like Thanksgiving turkey, Christmas beef tenderloin, or Easter ham.

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