vegetables-and-side-dishes
Brussels Sprouts Gratin
A rich, oven-baked Brussels sprouts gratin that turns a humble vegetable into a deeply comforting side dish. Roasted sprouts develop nutty, caramelized edges before being folded into a silky cream sauce flavored with garlic, Dijon, and a hint of nutmeg. Finished with Gruyère, Parmesan, and a golden breadcrumb crust, this gratin balances crisp, creamy, and savory in every bite — equally at home on a holiday table or beside a simple roast chicken.
Ingredients
Roasted Brussels Sprouts
- 1½–2 lb Brussels sprouts, trimmed and halved
- 2 tbsp olive oil
- 1 tsp kosher salt
- ½ tsp black pepper
Cream Sauce
- 2 tbsp unsalted butter
- 2 tbsp all-purpose flour
- 1½ cups heavy cream
- ½ cup whole milk
- 2 cloves garlic, minced
- 1 tsp Dijon mustard
- ½ tsp freshly grated nutmeg (optional)
- ½ tsp kosher salt
- ¼ tsp black pepper
Gratin Topping
- 1 cup Gruyère cheese, grated
- ½ cup Parmesan cheese, grated
- ½ cup breadcrumbs or panko
Instructions
- Preheat the oven to 400°F. Toss the halved Brussels sprouts with 2 tbsp olive oil, 1 tsp kosher salt, and ½ tsp black pepper. Arrange cut-side down on a baking sheet and roast for 20–25 minutes, until well-browned and just tender.
- While the sprouts roast, melt 2 tbsp butter in a saucepan over medium heat. Whisk in 2 tbsp flour and cook for 1 minute, stirring constantly, until lightly golden.
- Slowly whisk in 1½ cups heavy cream and ½ cup whole milk. Add the minced garlic, Dijon mustard, nutmeg (if using), ½ tsp kosher salt, and ¼ tsp black pepper. Simmer gently until the sauce thickens enough to coat the back of a spoon.
- Stir in ¾ cup of the Gruyère and ¼ cup of the Parmesan until fully melted and smooth. Taste and adjust seasoning if needed.
- Reduce the oven temperature to 375°F. Butter a baking dish and add the roasted Brussels sprouts. Pour the cheese sauce evenly over the sprouts and gently toss to coat.
- In a small bowl, combine the breadcrumbs with the remaining Gruyère and Parmesan. Sprinkle evenly over the gratin.
- Bake for 20–25 minutes, until bubbling and golden on top. For extra browning, broil for 1–2 minutes, watching closely.
- Let rest for 5 minutes before serving to allow the sauce to set slightly.
Notes
- For extra depth, add ½ cup caramelized onions or crispy bacon bits to the gratin before baking.
- A splash of dry white wine can be added to the cream sauce for a brighter, French-style finish.
- For a lighter version, substitute half-and-half for the heavy cream and reduce cheese slightly.