Creamy Crab and Shrimp Au Gratin Bake

This is the kind of seafood casserole that disappears fast once it hits the table. Sweet crab and juicy shrimp get folded into a rich Parmesan cream sauce, then topped with melted mozzarella and a golden buttery breadcrumb crust. It’s decadent, comforting, and perfect for a special dinner or gathering.

Why You’ll Love This Recipe

• Two seafoods, one indulgent bake. Crab and shrimp both bring rich flavor to this casserole.
• Rich Parmesan cream sauce. Smooth, savory, and coating every bite generously.
• That crisp au gratin topping. Buttery panko breadcrumbs add the perfect crunchy contrast.
• Great for a crowd. Serves 6, making it perfect for holidays, potlucks, or family dinners.

Ingredients

• 1 lb large shrimp, peeled and deveined
• 8 oz lump crab meat, drained and checked for shells
• 2 tbsp unsalted butter
• 3 garlic cloves, minced
• 2 tbsp all-purpose flour
• 1½ cups heavy cream
• ½ cup seafood or chicken broth
• ¾ cup freshly grated Parmesan cheese
• 1 cup shredded mozzarella cheese
• ½ cup panko breadcrumbs
• 2 tbsp melted butter
• 1 tsp Old Bay seasoning
• ½ tsp garlic powder
• ½ tsp paprika
• ¼ tsp black pepper
• Salt, to taste
• 1 tbsp fresh lemon juice
• 2 tbsp fresh chives, chopped

How to Make Creamy Crab and Shrimp Au Gratin Bake

1. Prepare the shrimp. Preheat the oven to 375°F (190°C). Pat the shrimp dry and season with Old Bay, paprika, garlic powder, black pepper, and a little salt.

2. Sear the shrimp. Melt 1 tablespoon butter in a large skillet over medium-high heat. Add the shrimp and cook for about 1 minute per side, just until they begin turning pink. Remove and set aside.

3. Make the creamy sauce. Add the remaining 1 tablespoon butter and garlic to the skillet. Cook for 30 seconds, then stir in the flour. Gradually whisk in the broth and heavy cream. Simmer gently for 3 to 4 minutes until the sauce begins to thicken.

4. Add the Parmesan. Reduce the heat to low and stir in the Parmesan until melted and smooth. Add the lemon juice and adjust the seasoning if needed.

5. Add the crab and shrimp. Gently fold the lump crab and most of the shrimp into the creamy Parmesan sauce, keeping the crab pieces as intact as possible.

6. Assemble the seafood bake. Transfer the creamy crab and shrimp mixture to a baking dish. Arrange the remaining shrimp over the top and sprinkle evenly with mozzarella.

7. Add the golden topping. Mix the panko breadcrumbs with 2 tablespoons melted butter. Sprinkle the buttery breadcrumbs over the mozzarella for a crisp, golden au gratin topping.

8. Bake until golden. Bake for 20 to 25 minutes, until the creamy seafood casserole is bubbling around the edges and the cheese is melted. Broil briefly if needed for a deeper golden finish.

9. Finish and serve. Sprinkle with fresh chives and let the crab and shrimp au gratin rest for about 5 minutes before serving.

Tips for the Best Crab and Shrimp Au Gratin

• Don’t overcook the shrimp in the initial sear. They’ll finish cooking in the oven, so just getting them to start turning pink is enough.
• Fold the crab in gently. A light hand keeps the lump pieces intact instead of shredding them into the sauce.
• Whisk the flour and liquids together gradually to avoid lumps in the cream sauce.
• Watch closely if broiling at the end. A quick broil deepens the golden color, but it can go too far quickly if left unattended.

What to Serve with Crab and Shrimp Au Gratin

A simple green salad with a light vinaigrette pairs nicely, cutting through the richness of the dish. Crusty bread also makes a great addition for scooping up any extra sauce.

Frequently Asked Questions