Cheesy Brussels Sprouts Gratin with Parmesan
This easy side dish features lightly roasted Brussels sprouts baked in a creamy parmesan sauce until bubbly and golden.
- Prep15 min
- Cook25 min
- Total40 min
- DifficultyEasy
- Servings4
This Brussels sprouts gratin is a wonderful way to enjoy these little green gems. The sprouts are first roasted to bring out their natural sweetness, then they are smothered in a rich, creamy parmesan sauce and baked until the cheese melts and bubbles.
It is a perfect side dish for Thanksgiving, Christmas, or any family dinner. The combination of tender roasted sprouts and a velvety cheese sauce is simply irresistible, and it comes together in under an hour.
Ingredients
Servings
Converted amounts are rounded.
Method
- Preheat your oven to 425°F.
- Place the trimmed and halved Brussels sprouts in an 8x11-inch baking dish. Drizzle with olive oil, then season with salt, pepper, and garlic powder. Toss everything together so the sprouts are evenly coated.
- Roast the Brussels sprouts in the preheated oven until they are tender, about 10 to 15 minutes, depending on their size. Give them a stir halfway through the roasting time.
- While the sprouts are roasting, prepare the sauce. In a small saucepan over medium heat, melt the butter. Add the minced onion and cook, stirring occasionally, until the onion becomes translucent, about 5 minutes.
- Sprinkle the flour and mustard powder over the onion. Stir constantly with a wooden spoon until the flour is fully incorporated and the mixture looks smooth, about 1 to 2 minutes.
- Slowly pour in the milk while stirring continuously. Keep stirring until the sauce thickens to a creamy consistency. Remove the saucepan from the heat.
- Add ¼ cup of the grated parmesan cheese to the sauce and stir until the cheese is completely melted and the sauce is smooth.
- Once the Brussels sprouts are roasted, pour the prepared sauce evenly over them. Sprinkle the remaining ¼ cup of parmesan cheese on top.
- Return the dish to the oven and bake for another 10 to 15 minutes, until the cheese is melted and the sauce is bubbly. Serve immediately.
💡 Tips
- For extra crispiness, you can broil the gratin for the last 1-2 minutes of baking, watching carefully so it doesn't burn.
- If you prefer a lighter sauce, you can use low-fat milk, but the sauce may be slightly less creamy.
- Freshly grated parmesan melts better and gives a smoother sauce than pre-shredded cheese.
Inspired by a recipe from FeelGoodFoodie