Broccolini Casserole Recipe
- 3 Tbsp. olive oil, divided
- 12 ounces cremini mushrooms, thickly sliced
- ½ cup (3 large) finely chopped shallots
- 2 garlic cloves, finely chopped
- 2 tsp. chopped fresh thyme
- ¼ cup dry white wine
- 1½ Tbsp. all-purpose flour
- 1¾ cups whole milk
- ½ cup heavy cream
- 1 cup finely grated Parmesan, divided
- 2 bunches (about 1 pound) broccolini, trimmed and blanched for 30 seconds
- ½ cup panko crumbs
Active time: 10 minutes
Total time: 35 minutes
Position a rack in center of oven and preheat to 450°. In a large, heavy skillet over medium-high heat, add 2 Tbsp. oil and mushrooms. Cook until tender, about 6 minutes. Add shallots, garlic, and thyme; cook until shallots soften, about 3 minutes. Add wine and simmer until wine evaporates, about 20 seconds. Sprinkle flour over top and stir to blend. Stir in milk and cream and bring to a boil. Reduce heat to medium and simmer gently, stirring, until sauce thickens, 3 to 5 minutes. Stir in ¼ cup Parmesan and remove from heat. Season with salt and pepper.
Pour half of mushroom mixture into an 8" baking dish. Arrange broccolini over mushrooms and top with remaining mixture.
In a medium bowl, mix panko, remaining ¾ cup Parmesan, and remaining 1 Tbsp. oil, then sprinkle mixture over top of casserole. Bake until panko is golden brown, about 12 minutes.
To make ahead
Prepare panko mixture up to 2 days ahead; blanch and drain broccolini up to 1 day ahead. Cover and refrigerate both.