brussels sprouts gratin in a white baking dish

Three Cheese Bacon Brussels Sprouts Gratin

Three Cheese Bacon Brussels Sprouts Gratin is the ultimate in indulgent vegetable side dishes. Featuring three different cheeses, crispy bacon, and walnuts, this casserole is the perfect accompaniment for your next fall dinner or holiday meal.

Brussels Sprouts Au Gratin – Low Carb, Keto, LCHF, Grain-free, Gluten-free, Sugar-free

serving of brussels sprouts gratin on a white plate

I will eat brussels sprouts year round. I know it’s traditionally a fall vegetable, but I’m telling you, that makes no difference in our house. Brussels sprouts are the kind of vegetable that I’ll put in anything, but when you pair them with gruyere, gorgonzola, bacon, and walnuts, some kind of magic occurs. This is the kind of side dish that will get people running for seconds and thirds. It’s holiday-worthy. Epic, really. I promise this recipe will be a brussels sprouts dish to remember, even for those that may not share my unwavering support of this vegetable.

How to make Creamy Brussels Sprouts Au Gratin


  • Brussels Sprouts
  • Bacon
  • Shallot
  • Butter
  • Walnuts
  • Garlic
  • Heavy cream
  • Gruyere cheese
  • Gorgonzola cheese
  • Parmesan cheese
  • Dijon mustard
a dish of bacon brussels sprouts gratin with a spoon

Some tips, tricks, and take-aways about the Cheesy Brussels Sprouts Casserole with Bacon recipe and process:

What does au gratin mean? A little kitchen wisdom for you:  the term au gratin refers to a technique that includes topping with bread crumbs and/or cheese and baking to achieve a golden crust. Since we don’t do bread crumbs, a nice layer of melty, crunchy cheese will do the trick here, but just know that a French chef may not agree with me here.

Char your brussels sprouts in a hot saute pan before baking. I know it looks like an extra step to cook your sprouts in a pan before baking, but hear me out. Pre-cooking your brussels sprouts will actually save you in the long run. The longer the sprouts sit in the oven, the more they will cook into that mushy pea green hot mess of yesteryear. There is nothing more unattractive than overcooked vegetables. Char your sprouts in either oil or butter in a hot saute pan before adding the cheese sauce mixture and baking. You’ll start the cooking process so that you won’t have to bake the heck of it later.

Use your broiler for an extra crispy golden brown crust on top. I popped my casserole under the broiler for a few minutes just before serving. I love that golden brown cheesy top to dig into. A little blister on your cheese always looks classy too. Just don’t walk away!  A split second more and you’ll singe it. Full disclosure: I was about 45 seconds from disaster in the pictures I posted for you. I’ve never moved so fast in my life to rescue that au gratin.

a serving of gratin on a white plate with a fork

Other Low Carb Vegetable Side Dish Recipes

Three Cheese Bacon Brussels Sprouts Gratin
Yield: 8

Three Cheese Bacon Brussels Sprouts Gratin

Prep Time: 15 minutes
Cook Time: 20 minutes
Total Time: 35 minutes

Three Cheese Bacon Brussels Sprouts Gratin is the ultimate in indulgent vegetable side dishes. Featuring three different cheeses, crispy bacon, and walnuts, this casserole is the perfect accompaniment for your next fall dinner or holiday meal.


  • 4 slices uncured bacon, sliced into 1/2 inch pieces
  • 2 pounds brussels sprouts, trimmed and halved
  • 1 Tbsp butter
  • 1 Tbsp bacon drippings (reserved from cooking)
  • 3 Tbsp diced shallot
  • 2 garlic cloves, minced or pressed
  • 1/4 cup walnut pieces
  • 1 cup heavy cream
  • 1/2 tsp dijon mustard
  • 1/2 cup gruyere cheese, shredded
  • 1/4 cup gorgonzola cheese, crumbled
  • 1/4 cup parmesan cheese, shredded
  • 1/2 tsp freshly ground black pepper
  • Sea salt


  1. Preheat oven to 400 degrees.
  2. In a large skillet, cook bacon over medium heat until crispy, about 6-8 minutes. Drain on a paper towel lined plate, reserving 1 Tbsp of drippings. Set bacon aside.
  3. Return skillet to medium high heat. Add reserved bacon drippings and butter. Add shallots, garlic, and brussels sprouts. Add a pinch of salt. Cook, stirring occasionally and allow sprouts to blister/char, about 8 minutes.
  4. While sprouts cook, combine cream, mustard, cheeses, and pepper in a small bowl. Mix to combine.
  5. Pour contents of skillet into a large oven proof baking dish. Sprinkle with walnuts and pour sauce mixture over the top.
  6. Bake for about 15-20 minutes until cheese sauce is bubbly and golden brown. Switch oven to broil if you need more color/crunch. Broil for only 1-2 minutes; do not leave unattended as the top can burn quickly.


I chose not to add salt to the recipe because every bacon is slightly different. Season to taste just to be safe.

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 269Total Fat: 22gSaturated Fat: 12gTrans Fat: 1gUnsaturated Fat: 9gCholesterol: 57mgSodium: 316mgCarbohydrates: 11gNet Carbohydrates: 8gFiber: 3gSugar: 3gProtein: 10g

Did you make this recipe? Let me know how it turned out! Leave a comment below and make sure to join the @noshinandnumnums community on instagram or facebook and tag me in your cooking pictures! 

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