Lightly browned and bubbling with a creamy Gruyère sauce, you’ll find that Cheesy Brussels Sprouts au Gratin is irresistible. A perfect dish to serve for Thanksgiving, you won’t want to wait that long to try this delicious gratin.

Cheesy brussels sprouts gratin with a spoon scooping out one big cheesy scoop.

I can’t believe we’re thinking about Thanksgiving already! It seems like we were just talking about inflatable rafts and sunscreen lotion. Only take a look at the shelves in your grocery store, though, and you’ll know that fall has arrived. All of the cool weather crops are displayed, inviting us to make the transition from summer eating (watermelons, cucumbers, corn on the cob, strawberries!) to autumn foods: winter squash, apples, pumpkins, brightly colored corn, cabbage, and Brussels sprouts. I love the flavors of fall, don’t you? 

I especially love these cheesy Brussels sprouts! Roasted lightly, then smothered with a creamy Gruyère cheese sauce, with a hint of nutmeg and thyme, and baked again until lightly browned and bubbling, these Brussels sprouts are a culinary delight! Even people who are professed Brussels sprouts haters will be converted by the creaminess and flavor of this mouthwatering gratin. 

Seriously, when we were testing this recipe, we could hardly wait for this casserole to come out of the oven and we weren’t disappointed! 

Overhead view of a pan of brussels sprouts gratin.

About these Cheesy Brussels Sprouts:

Cheesy Brussels sprouts are a gratin. You may be more familiar with potatoes cooked au gratin, or scalloped potatoes, which are basically the same thing. What does “gratin” mean? In French, “au gratin” means “by grating.” In traditional French cooking, a gratin is a made in a shallow dish containing potatoes, vegetables, or even seafood, covered with a lightly browned crust of  bread crumbs or cheese.

Au gratin can also mean casserole, or scraping from the pan, and I guarantee you’ll be scraping the pan of this Brussels sprouts gratin for every last delicious morsel.  

Brussels gratin in a white baking dish. Fresh thyme also pictured.

Did you know?

There is some confusion about how to spell the name of this tiny green cabbage-like vegetable. Many people use the spelling Brussel sprouts, omitting the “s” at the end of the word Brussels. Brussels sprouts are actually named for the Belgium city of Brussels so you definitely spell it with the “s” at the end. We don’t want to offend the good people of Brussels! 

(There’s some disagreement about whether the “B” should be capitalized or not, but we’re not going there. Just remember the “s” and we’re good to go!)

You’ll want to have all the ingredients for making this recipe prepared before you begin cooking it. Wash and trim the Brussels sprouts, grate the Gruyère, measure the milk, flour, and butter for the white sauce, grate the nutmeg, and chop the thyme. Get your oven preheating to 400ºF and prepare your baking dish. You’ll want to use a nice shallow glass dish for this recipe because you’ll be serving the gratin right from the dish. 

Close up view of Brussels sprouts and cheese in a white baking dish.


Prepping and pruning those tiny green cabbages can seem tricky the first time you do it.


  • Look for firm, compact, dark green Brussels sprouts, that don’t have worm holes and aren’t shriveled.
  • Rinse them well in a colander under running water.
  • Using a sharp paring knife, cut off the tough stem, about even with the edge of the sprout.
  • Peel away discolored or wilted outer leaves.
  • For this recipe, I cut the sprouts in half lengthwise. Whether or not you cut your sprouts depends on their size. You want them to be uniformly bite-sized. 
  • If you’d like a visual of how to prep Brussels sprouts, take a look at this informative YouTube video

I toss the prepped Brussels sprouts with a bit of olive oil, season with salt and pepper, spread them in the baking dish, and roast them for about 20 minutes, or until they’re just beginning to brown slightly. Meanwhile, I prepare the white sauce on the stovetop, whisking in the cheese, nutmeg, and herbs when the sauce has thickened.

Pour this creamy cheese sauce over the sprouts (you might want to reserve a spoonful or two for tasting because it’s soooo good), sprinkle the top with additional grated Gruyère, and pop the dish back into the oven for 20 minutes or so, until it’s brown and bubbling. Let it cool for 5-10 minutes before serving, to let the flavors meld. Serve it right from the baking dish. 

Cheesy brussels gratin being scooped out a white baking dish.

How to make this cheesy Brussels sprouts recipe your own:

  • I like the slightly nutty flavor of Gruyère with this Brussels sprouts au gratin, but you could substitute another kind of cheese. Swiss cheese, sharp cheddar, Parmesan or Asiago would be fabulous as well. 
  • Brussels sprouts au gratin with bacon or pancetta added would be really great, too. Just cut it into 1 inch pieces, cook until done, drain, and add it with the cheese. 
  • You could experiment with the spices and herbs. If you love garlic, try adding a bit of garlic powder to the white sauce. Paprika would be a good addition, as well, maybe sprinkled on the top to add a little color. If you’re not a nutmeg fan, leave it out. It will still taste great!
  • Lighten it up by using low fat milk to make the white sauce. It won’t be quite as creamy but you’ll save some calories and fat. If you’re really looking to cut calories, don’t mix any cheese into the white sauce and just sprinkle a half cup on top of the gratin before baking. 

Reheating and Storage Tips

This dish is really best eaten right away. If you do have leftovers, heat them gently in the oven until they’re heated through, or in the microwave. They will keep a couple of days in the fridge. 

Other great side dishes for Thanksgiving:

These cheesy Brussels sprouts would be a great side for Thanksgiving. Looking for more great recipes for that special day? I’ve got you covered!


I have joined up with a bunch of blogger friends for a Friendsgiving Virtual Potluck!

Be sure to check the recipes below out for wonderful Friendsgiving and Thanksgiving recipe and craft ideas!

Baked Brie with Honey & Walnuts from Kelley of Mountain Mama Cooks
Reindeer Bacon Cheddar Cheese Ball from Julie of Julie Blanner

Sauteed Kale and Brussels Sprout Salad with Cranberries and Walnuts from Shashi of Savory Spin
Creamy Brussels Sprouts Salad from Faith of An Edible Mosaic

Main Dishes
Savory Vegetable Crisp from Bree of Baked Bree
Rosemary Lamb Steaks from Danyelle of The Cubicle Chick
Turkey Pot Pie from Kelly of Eat Picks

Side Dishes
Fried Brussels Sprouts from Erin of The Almond Eater
Cheesy Horseradish Mashed Potato Casserole from Renee of Kudos Kitchen by Renee
Cranberry Cream Cheese Dip from April of April Golightly
Sauteed Garlic-Butter Mushrooms from Linda of Simply Healthyish Recipes
Easy Cheesy Hash Brown Casserole Recipe from Mel of Adventures of Mel
Cornbread Stuffing with Chorizo from Isabel of Isabel Eats
Bacon Brussels Sprouts from Kara of Kara J. Miller
Crockpot Sweet Potato Casserole from Jennifer of Show Me the Yummy
Amazing Gluten Free Thanksgiving Stuffing from Sommer of A Spicy Perspective
Pumpkin Caramelized Onion Gratin from Denise of Chez Us
Crockpot Mac & Cheese from Leanette Fernandez of Funtastic Life

Spiced Pumpkin Margarita from Sharon of Cupcakes and Cutlery

Sourdough Pull Apart Rolls from Erica of Buttered Side Up
How to Make Homemade Butterhorn Rolls from Mel of Flour on My Fingers
Sweet Dinner Rolls from Jocelyn of Grandbaby Cakes
Parker House Rolls from Irvin of Eat the Love

Sugar Pie from Julie of The Little Kitchen
Oatmeal Apple Crisp from Julie of Peanut Butter Fingers
Pumpkin Pie Milkshake from Eden of Sugar and Charm
Strudel Pastry from Justine of The Typical Mom
Tahini Hawaij Pumpkin Pie from Amy of What Jew Wanna Eat
Turkey Cookies from Meaghan of The Decorated Cookie
Mini Apple Pie Bites from Lynsey of MoscatoMom
Kabocha squash pie from Hilah of hilahcooking
Pecan Pie Cupcakes from Courtney of Pizzazzerie
Coconut Cream Pie from Schnelle of Brooklyn Active Mama
Chocolate chip cheesecake from Jeannette of Hispana Global
Chocolate Pecan Pie from Kate of I Heart Eating
Mini Pumpkin Cheesecakes from Chelsea of Someday I’ll Learn
Turkey Donut Race Cars For Thanksgiving Treats from Theresa of Chewable Structures

Crafts and Centerpieces
Cinnamon Stick Holiday Candle Place Setting from Alli of Made with HAPPY
Metallic Pumpkin Luminaries from Amy of As The Bunny Hops
Easy centerpiece that will stun + party favor from Noelle of Oh Happy Play

Cheesy brussels sprouts gratin with a spoon scooping out one big cheesy scoop.

Cheesy Brussels Sprouts au Gratin

Yield: 8 servings
Prep Time: 15 minutes
Cook Time: 40 minutes
Additional Time: 10 minutes
Total Time: 1 hour 5 minutes

Lightly browned and bubbling with a creamy Gruyère sauce, you'll find that Cheesy Brussels Sprouts au Gratin is irresistible. A perfect dish to serve for Thanksgiving, you won't want to wait that long to try this delicious gratin.


  • 2 pounds Brussels sprouts
  • 1 tablespoon olive oil
  • 1/4 teaspoon kosher salt
  • 1/8 teaspoon ground black pepper
  • 2 tablespoons unsalted butter
  • 1/2 medium yellow onion, diced (about ½ cup)
  • 2 tablespoons all-purpose flour
  • 1 3/4 cups whole milk
  • 1 teaspoon roughly chopped fresh thyme, or ½ teaspoon dried thyme
  • ¼ teaspoon freshly grated nutmeg
  • 4 ounces Gruyère cheese, shredded and divided


  1. To prepare Brussels sprouts, rinse well. Trim off bottom (stem) end and remove any brown or tough outer leaves. Cut in half from top to bottom.
  2. Preheat oven to 400ºF. Spray a 9 by 13 baking dish with nonstick baking spray. 
  3. Mix Brussels sprouts with olive oil, salt, and pepper, and add to prepared baking dish.
  4. Bake for 20 minutes or until starting to brown. Remove from oven.
  5. Meanwhile, while Brussels sprouts are roasting, in a medium saucepan over medium heat, melt butter. Add onions and saute, stirring constantly, until translucent, or about 2 minutes. 
  6. Add flour and continue to stir or whisk for 1 minute.
  7. Slowly add the milk, stirring constantly, and cook over medium-low heat until thickened, 12 minutes.
  8. Add thyme and nutmeg to the sauce, and stir to combine. Stir in half of the cheese until melted. Pour cheese sauce over Brussels sprouts, stirring lightly to combine. Top with remaining cheese. 
  9. Bake for 20 minutes, or until top is starting to brown and gratin is bubbling. 
  10. Let sit 5-10 minutes before serving.


  • You could add bacon or pancetta to the gratin. Cook diced bacon or pancetta until crisp, drain well, and stir into the sauce with the thyme and nutmeg.
Nutrition Information:
Yield: 8 Serving Size: 1 of 8
Amount Per Serving: Calories: 181Total Fat: 12gSaturated Fat: 6gTrans Fat: 0gUnsaturated Fat: 5gCholesterol: 27mgSodium: 206mgCarbohydrates: 13gFiber: 3gSugar: 5gProtein: 8g sometimes provides nutritional information, but these figures should be considered estimates, as they are not calculated by a registered dietitian. Please consult a medical professional for any specific nutrition, diet, or allergy advice.

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Verdict: These are dangerously addicting for me…I can never stop eating them.
Husband’s take: Ben is OBSESSED with these. I mean, they’re super cheesy and so creamy, who wouldn’t love these?
Changes I would make: None are necessary but bacon is never ever a bad idea.
Difficulty: Easy to moderate. If you’re not super familiar with making white sauces, read through all the directions first and make sure you have your ingredients prepped, measured, and ready to go (in other words, grate the cheese before you start making the sauce). If you do that, you’ll have no problem at all making this recipe!