Ingredients:
- 6 tablespoons unsalted butter, divided
- 1 1/2 lbs Brussels sprouts, trimmed and halved
- 8 ounces button or cremini mushrooms, sliced
- 1 medium onion, chopped
- Salt and pepper
- 2 cloves garlic, minced
- 2 tablespoons all-purpose flour
- 1 cup chicken or vegetable stock
- 1 cup half and half
- 1 cup panko breadcrumbs
- 1 6-ounce can French fried onions
Directions:
- Preheat oven to 375°F. Butter a 9×13-inch casserole dish.
- Set aside.
- Melt 2 tablespoons butter in large skillet set over medium heat.
- Add Brussels sprouts and cook until browned, about 5 minutes.
- Transfer to separate bowl and set aside.
- Add mushrooms and onions to skillet, season with salt and pepper, and cook until soft, about 5-6 minutes.
- Add garlic and cook for 1 minute more.
- Add to bowl with Brussels sprouts.
- Melt 2 tablespoons butter in medium skillet.
- Add flour and whisk to form thick paste.
- Add chicken or vegetable stock gradually while whisking constantly.
- Whisk in half and half.
- Increase heat to medium high and bring to boil, whisking frequently.
- Simmer for about 5 minutes until thickened.
- Season with salt and pepper to taste.
- Combine Brussels sprouts mixture with sauce and pour into prepared casserole dish.
- Melt remaining 2 tablespoons of butter and combine with breadcrumbs in medium bowl.
- Add French fried onions.
- Scatter mixture on top of Brussels sprouts mixture and bake casserole until bubbly and topping is brown, about 20-25 minutes.
- Note: This casserole can be prepared ahead of time.
- Cover unbaked casserole with plastic wrap and chill in the fridge for up to 1 day.
- Remove plastic wrap and bake, increasing time to 35-40 minutes.