Seafood Casserole
A rich and creamy baked seafood casserole loaded with shrimp and white fish, topped with a golden, buttery breadcrumb crust.
Equipment
- 9x13 baking dish
- Large skillet
- Saucepan
- whisk
- Mixing bowls
Ingredients
Seafood and Sauce
- 1 lb shrimp peeled and deveined
- 1 lb white fish fillets cod or tilapia, cut into chunks
- 3 tbsp unsalted butter
- 3 tbsp all-purpose flour
- 2 cups milk
- ½ cup chicken or seafood broth
- ½ cup grated parmesan cheese
- ½ tsp garlic powder
- ½ tsp paprika
- Salt and pepper to taste
- 2 tbsp fresh lemon juice
- 2 tbsp chopped fresh parsley
Breadcrumb Topping
- 1 cup breadcrumbs panko or regular
- 3 tbsp unsalted butter melted
- 2 tbsp grated parmesan cheese
Instructions
Prepare the Seafood and Make the Sauce
- Season the shrimp and fish chunks lightly with salt and pepper, then set aside. In a large skillet over medium heat, melt the butter and whisk in the flour, cooking for about 1-2 minutes to form a roux, stirring constantly to prevent it from browning too much or clumping.
- Gradually whisk in the milk and broth, a little at a time, whisking continuously until the mixture is smooth and starts to thicken, which usually takes about 4-5 minutes. Stir in the parmesan cheese, garlic powder, and paprika, continuing to whisk until the cheese is fully melted and the sauce is smooth and creamy.
Combine and Assemble
- Add the seasoned shrimp and fish chunks directly into the sauce, gently folding them in so they're evenly coated without breaking apart the fish pieces too much. Cook for 2-3 minutes over low heat, just until the seafood starts to turn opaque but isn't fully cooked through yet, since it will finish cooking in the oven.
- Stir in the lemon juice and fresh parsley, then pour the entire mixture into a greased 9x13 baking dish, spreading it out into an even layer with a spatula.
Add the Topping and Bake
- In a small bowl, combine the breadcrumbs, melted butter, and parmesan cheese, stirring until the crumbs are evenly coated and slightly clumped together. Sprinkle the breadcrumb mixture evenly over the top of the seafood mixture in the baking dish, covering it completely.
- Bake at 375°F (190°C) for 20-25 minutes, until the topping is golden brown and the filling is bubbling around the edges. Let the casserole rest for 5-10 minutes before serving, since the sauce needs a few minutes to set slightly for cleaner scooping.
Notes
- Don't fully cook the seafood in the skillet before baking, since it will continue cooking in the oven and can become tough or rubbery if overcooked at both stages.
- Whisking the milk into the roux gradually, rather than all at once, is key to avoiding a lumpy sauce, so take your time during that step even if it feels slow.
- Using freshly grated parmesan rather than the pre-shredded, bagged variety helps the sauce melt more smoothly and avoids a grainy texture.
- If the breadcrumb topping is browning too quickly before the filling is fully bubbling, loosely tent the dish with foil for the remaining bake time.
- Letting the casserole rest briefly after baking makes a real difference in how cleanly it scoops and serves, so try not to skip that short resting period.