INGREDIENTS
2 tbsp olive oil
6 tbsp unsalted butter divided
½ cup onion chopped
½ cup green bell pepper seeded and chopped
½ cup celery chopped
¼ cup scallions sliced, white and green parts
3 cloves garlic minced
2 16 oz containers oysters fresh, drained and rinsed
8 oz mushrooms sliced
2 tbsp all-purpose flour heaping
1 cup half and half
1 tbsp fresh lemon juice
1 tbsp Worcestershire sauce
1 tbsp hot sauce
¼ cup Parmesan cheese grated
1 tsp Kosher salt
½ tsp freshly ground black pepper
1 cup breadcrumbs fresh, chopped from a loaf of bread with the crust mostly removed
DIRECTIONS
Preheat oven to 400°F.
Heat the olive oil over medium-high heat in a large skillet. Stir in 2 tablespoons of the butter until melted. Add onion, bell pepper, and celery, and cook until soft, about 5 to 7 minutes. Add the scallions and garlic and cook for another minute.
Add oysters and mushrooms and bring to a simmer, stirring often, 5 minutes. Set aside.
Melt 2 tablespoons of the butter in a medium saucepan over medium heat. Whisk in flour, and cook, whisking constantly, until smooth, 1 minute.
Stir in half and half, lemon juice, Worcestershire sauce, hot sauce, salt, and pepper, whisking constantly, until very thick and beginning to bubble, about 2 to 5 minutes. Stir in Parmesan cheese until melted, about 1 more minute.
Using a fine-mesh sieve or colander, strain the oyster mixture, and discard the liquid.
Add oyster mixture to cheese sauce and stir until fully incorporated.
Spread mixture in an 11x7-inch baking dish.
Melt the remaining 2 tablespoons of butter, then toss breadcrumbs with melted butter and a pinch of salt. Sprinkle the breadcrumbs over the oyster mixture.
Bake for 15 minutes, or until bubbly. Remove the casserole from the oven and move the rack to the 2nd level under the broiler. Place the casserole under the broiler for 1 to 2 minutes, until the breadcrumb topping is slightly browned. Be sure to watch closely and don’t let it burn, as broilers vary! Remove from oven and serve at once.
