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A wooden spoon sitting in casserole dish filled with cooked oyster casserole, with one serving missing from the dish.

Oyster Casserole

Course: Casserole
Cuisine: American
Keyword: holiday side dishes, Oysters, Southern U.S. recipes
Prep Time: 20 minutes
Cook Time: 17 minutes
Total Time: 37 minutes
Servings: 4 people
Calories: 371kcal
This Oyster Casserole is a favorite on holiday tables all over, but especially in the Southern United States. We just love the briny flavor of the fresh oysters, combined with mushrooms, veggies, bread crumb topping....unbelievably delicious!
Print Recipe

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
  • ½ 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

Instructions

  • 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. Watch closely!!! Don't let burn, as broilers vary! Remove from oven and serve at once.

Video

Notes

This casserole is best with fresh oysters.  Fresh oysters can be found canned, or in plastic containers in the seafood section of many well-stocked supermarkets or gourmet food markets.  Or, at your local fish market.  We don't recommend using boiled or smoked oysters.  Shucking fresh oysters is an option, too.  You'll need about 4 lbs of them.
We recommend using half and half for the sauce, however you can substitute whole milk, or heavy cream, or a combination of any of these.
For the hot sauce, we use Louisana hot sauce, but Tobasco, Crystals, or Franks are all great choices.  The hot sauce adds a small amount of spice, but very little.  If you want no heat at all, simply omit the hot sauce, or go with a smaller amount (a couple of dashes). 
The casserole can be prepared up to 4 hours in advance of baking.  Don't top with the breadcrumbs until just before baking.
IMPORTANT: Keep an eye on the casserole once you place it under the broiler.  It does not take long at all to brown the breadcrumbs.  Broilers vary from oven to oven, so don't let them burn!

Nutrition

Calories: 371kcal | Carbohydrates: 30g | Protein: 10g | Fat: 16g | Saturated Fat: 8g | Cholesterol: 61mg | Sodium: 1037mg | Potassium: 410mg | Fiber: 3g | Sugar: 5g | Vitamin A: 814IU | Vitamin C: 22mg | Calcium: 179mg | Iron: 2mg