Brussels Sprouts Gratin

a wooden spoon scooping some gratin out of the baking dish.

Fresh Brussels sprouts baked up in a rich and creamy Gruyere cheese sauce and topped with a crispy bacon and breadcrumb topping. This is a holiday must-have side dish!

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Author: April Anderson

Servings: servings

Prep Time: 1

Cook Time: 20

Total Time: 1 20

Ingredients

3 slices bacon chopped
1/2 cup unsalted butter divided
1 1/2 pounds brussels sprouts stems and outer leaves removed and halved (if extra large cut into quarters)
3 tablespoons all-purpose flour
2 cups 2% milk
1/2 cup heavy cream
1/2 large yellow onion peeled
2 1/2 cups shredded gruyere cheese
1/2 teaspoon kosher salt
1 1/2 cups breadcrumbs see note
1/4 cup grated parmesan cheese
1/4 teaspoon ground black pepper

Instructions

Preheat oven to 375°F.
In a large pan, cook the chopped bacon over medium heat until it's crispy. Remove it from the pan (leave the fat in the pan) and set aside.
In the same pan, melt 2 tablespoons of butter in the bacon fat. Add the Brussels sprouts and cook them for 15 to 20 minutes, or until fork tender. Once cooked remove them from the heat and set aside.
Turn the heat off until the pan cools off a bit before making the bechamel sauce. Once it's cooled, turn the heat to low and add another 2 tablespoons of butter to the pan. Once it's melted and frothy, sprinkle in the flour. Stir it all together until it forms a paste.
Slowly pour in the milk and cream whisking continuously to ensure no lumps form and the flour and butter fully incorporate into the milk and cream. Raise the heat to bring the mixture to a simmer.
Place the onion in the milk (you don't need to chop it first - place it in whole). Simmer the mixture for about 20 minutes or so, or until it has reduced enough to coat the back of a spoon. You will need to stir frequently to ensure the bechamel does not burn at the bottom of the pan. Once reduced remove the onion and discard it.
Stir in 2 cups of the grated Gruyere cheese (save the rest for the top of the gratin). Once the cheese has melted season the sauce with the salt (be sure to give it a taste and add more to suit your taste). Stir in the cooked Brussels sprouts and pour it all into an 8 x 8 baking dish. Top with the remaining Gruyere cheese.
In a small bowl, combine the breadcrumbs with the grated Parmesan cheese, 2 tablespoons melted butter, and ground black pepper. Top the Brussels sprouts with the bread crumbs and sprinkle the cooked bacon over the breadcrumbs. Take the last 2 tablespoons of butter, cut it into small pieces, and spread them out evenly over the top of the breadcrumbs and bacon.
Bake at 375°F for 20 minutes. After 20 minutes turn the broiler on and move the baking dish to the top rack. Broil the dish for a few minutes, just until the breadcrumbs turn a brown and get really crispy (keep an eye on it!). Remove from the oven and serve.

Notes

I keep white bread on hand in the freezer to use for bread crumbs. 3-4 slices are all you need for this recipe - thaw them and then pulse them in a food processor to turn them into crumbs. You can substitute dried breadcrumbs or panko, if you don't want to use bread.

You can make different parts of the recipe ahead of time. You can cook the bacon and Brussels sprouts the day before and keep them in the fridge until you're ready to assemble the dish.

Nutrition Estimate

Course: Side Dish

Cuisine: American

Keyword: brussels sprouts gratin