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Shrimp and Crab Au Gratin Casserole topped with crispy breadcrumbs

Shrimp & Crab Au Gratin Casserole

A delicious casserole combining shrimp and lump crab meat in a creamy, cheesy sauce, perfect for family gatherings or cozy nights in.
Prep Time 15 minutes
Cook Time 25 minutes
Total Time 40 minutes
Course Casserole, Main Course
Cuisine American, Seafood
Servings 6 servings
Calories 450 kcal

Ingredients
  

Seafood

  • 1 lb shrimp, peeled & deveined Fresh shrimp adds a juicy, briny flavor.
  • 1 cup lump crab meat Tender, sweet crab meat elevates the dish.

Base

  • 2 tbsp butter Adds velvety texture.
  • 2 cloves garlic, minced Brings depth and warmth.
  • 2 tbsp all-purpose flour Acts as a thickening agent.
  • 1.5 cups milk or half-and-half Creates a luscious texture.

Cheeses

  • 1 cup shredded sharp cheddar Provides a bold, cheesy flavor.
  • 0.5 cup shredded mozzarella Melts beautifully for a gooey texture.
  • 0.25 cup grated Parmesan Adds a nutty finish.

Seasonings

  • 1 tsp Old Bay seasoning Brightens the dish.
  • to taste Salt & black pepper Essential for enhancing flavors.

Topping

  • 0.5 cup seasoned breadcrumbs Brings a crispy crunch.
  • 1 tbsp chopped parsley For garnish.

Instructions
 

Preparation

  • In a skillet, melt 1 tablespoon of butter over medium heat.
  • Add the shrimp and minced garlic, sautéing for about 2–3 minutes until the shrimp are just pink. Set aside.
  • In the same pan, melt the remaining 1 tablespoon of butter, stir in flour, and cook for 1 minute to form a roux.

Cooking

  • Slowly whisk in the milk or half-and-half, stirring continuously until the mixture thickens.
  • Add shredded cheddar, mozzarella, and Parmesan cheese, stirring until melted.
  • Mix in the cooked crab meat and sautéed shrimp, season with Old Bay, salt, and pepper.
  • Transfer to a greased baking dish, top with reserved shrimp and sprinkle with breadcrumbs.
  • Bake at 375°F for 20–25 minutes, until golden and bubbly. Broil for the last 2 minutes for extra crispness.

Serving

  • Garnish with chopped parsley and serve hot.

Notes

Use fresh seafood for the best flavor; frozen can work as a substitute. Consider adding jalapeños for a kick or sautéed vegetables for additional nutrition. Pairs well with salad, crusty bread, or roasted vegetables.
Keyword Baked Dish, casserole, Comfort Food, Seafood Dish, Shrimp & Crab