This baked seafood casserole is the kind of cozy dinner that makes everyone happy. It’s creamy, cheesy, and packed with tender shrimp, flaky fish, and sweet scallops. You mix everything in one dish, bake until bubbly, and serve it straight from the oven with a simple salad or crusty bread.
It’s approachable enough for a weeknight, but special enough for a Sunday dinner. If your family loves seafood but you don’t want to fuss with complicated steps, this is a great go-to recipe.
What Makes This Recipe So Good
- Fuss-free prep: Most of the work is chopping and stirring; the oven does the rest.
- Creamy and cheesy: A light, velvety sauce with melted cheese makes it comforting without being heavy.
- Flexible seafood mix: Use shrimp, fish, scallops, or crab—whatever you have on hand.
- Family-friendly flavors: Mild seasoning and a buttery topping keep it kid-approved.
- Great for leftovers: Reheats well for an easy lunch the next day.
Ingredients
- 1 pound shrimp, peeled and deveined (medium or large)
- 1/2 pound white fish fillets (cod, haddock, or tilapia), cut into bite-size pieces
- 1/2 pound sea scallops or bay scallops
- 1 cup lump crab meat (optional, but delicious)
- 2 tablespoons butter
- 1 tablespoon olive oil
- 1 small onion, finely diced
- 2 garlic cloves, minced
- 1 red bell pepper, diced
- 1 cup sliced mushrooms (optional)
- 1/2 cup dry white wine or seafood stock
- 1 cup heavy cream
- 1/2 cup whole milk or half-and-half
- 1 tablespoon Dijon mustard
- 1 teaspoon Old Bay or seafood seasoning
- 1/2 teaspoon paprika
- 1/2 teaspoon kosher salt, plus more to taste
- 1/4 teaspoon black pepper
- 1 cup shredded mozzarella or Monterey Jack cheese
- 1/2 cup grated Parmesan
- 2 tablespoons chopped fresh parsley or chives
- Juice of 1/2 lemon
- 1 cup panko breadcrumbs
- 2 tablespoons melted butter (for topping)
- Lemon wedges, for serving
Step-by-Step Instructions
- Preheat and prep: Heat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish.
- Pat seafood dry: Dry the shrimp, fish, and scallops with paper towels.
This helps them bake evenly and prevents watery sauce.
- Sauté aromatics: In a large skillet, warm the butter and olive oil over medium heat. Add onion and bell pepper, and cook 3–4 minutes until softened. Stir in garlic and mushrooms, and cook 2 minutes more.
- Deglaze: Pour in the white wine or seafood stock.
Simmer 2–3 minutes to reduce slightly and lift any browned bits from the pan.
- Make the sauce: Reduce heat to low. Stir in heavy cream, milk, Dijon, Old Bay, paprika, salt, and pepper. Simmer gently 3–4 minutes, stirring often, until slightly thickened.
Avoid boiling.
- Add cheese: Remove from heat and stir in mozzarella and half of the Parmesan until melted and smooth.
- Combine seafood: In a large bowl, toss the shrimp, fish, scallops, and crab (if using) with lemon juice and parsley. Sprinkle with a pinch of salt.
- Assemble: Spread the seafood mixture evenly in the baking dish. Pour the cheese sauce over the top and gently stir to coat.
- Make the topping: In a small bowl, combine panko, remaining Parmesan, and melted butter.
Sprinkle evenly over the casserole.
- Bake: Bake for 18–22 minutes, until the topping is golden and the sauce is bubbling around the edges. The shrimp should be pink and opaque, and the fish should flake easily.
- Rest and serve: Let the casserole rest for 5 minutes before serving. Garnish with extra herbs and serve with lemon wedges.
Storage Instructions
- Refrigerate: Cool completely, then cover and refrigerate for up to 2 days.
- Reheat: Warm in a 325°F (165°C) oven, covered, for 15–20 minutes, then uncover for 5 minutes to re-crisp the topping.
Add a splash of milk or stock if the sauce seems too thick.
- Freezing: Not ideal after baking due to dairy and seafood texture changes. If you must freeze, do it before baking, without the breadcrumb topping, for up to 1 month. Thaw in the fridge overnight, add the topping, then bake.
Benefits of This Recipe
- Balanced richness: Creamy sauce with a bright touch of lemon keeps it from feeling heavy.
- Customizable protein: Swap in what’s fresh or on sale, and adjust quantities easily.
- One-pan convenience: Everything bakes in one dish for easy serving and cleanup.
- Kid-friendly flavors: Mild spice and melty cheese make seafood approachable for picky eaters.
- Entertaining-ready: Looks and smells impressive with minimal effort.
Pitfalls to Watch Out For
- Overcooking seafood: Bake just until opaque and flaky.
Extra time can make it rubbery.
- Watery casserole: Always pat seafood dry. Don’t skip reducing the wine/stock and simmering the sauce.
- Boiling the cream: High heat can cause the sauce to separate. Keep it at a gentle simmer.
- Too salty: Seafood, cheese, and Old Bay add salt.
Taste the sauce before adding more.
- Soggy topping: Bake uncovered and use panko for the best crunch.
Variations You Can Try
- Lightened-up: Use half-and-half and reduce cheese by one-third. Add extra mushrooms and spinach for volume.
- Cajun twist: Swap Old Bay for Cajun seasoning, add a pinch of cayenne, and use pepper jack cheese.
- Lemon-herb: Add zest of 1 lemon to the sauce and finish with dill and chives.
- Garlic breadcrumb: Stir 1 minced garlic clove and a teaspoon of lemon zest into the panko topping.
- Gluten-free: Use gluten-free panko and check seasonings for hidden gluten. Thicken the sauce slightly longer instead of using flour (none used here).
- Veggie boost: Fold in baby spinach, peas, or steamed broccoli florets before baking.
- Pasta version: Mix in 8 ounces cooked, short pasta (like shells) and increase sauce by 1/2 cup milk.
FAQ
Can I use frozen seafood?
Yes, but thaw it completely in the fridge and pat very dry.
Excess moisture can thin the sauce and prevent browning.
What can I use instead of wine?
Use seafood stock or low-sodium chicken broth. A squeeze of lemon at the end keeps the brightness you’d get from wine.
How do I know the casserole is done?
Look for bubbling edges, a golden top, and shrimp that are pink and opaque. Fish should flake easily with a fork, and scallops should be opaque and springy.
Which cheese melts best here?
Mozzarella and Monterey Jack melt smoothly.
Parmesan adds a savory kick. Avoid aged cheddar if you want a silky sauce, as it can turn oily.
Can I make this ahead?
Yes. Assemble up to the point of adding the breadcrumb topping, cover, and refrigerate for up to 12 hours.
Add the topping and bake just before serving.
What should I serve with it?
Crusty bread, a simple green salad, roasted asparagus, or steamed green beans all pair well. Lemon wedges are a nice touch.
How spicy is this recipe?
It’s mild. If you want heat, add a pinch of red pepper flakes or use a spicier seasoning blend.
Can I leave out a type of seafood?
Absolutely.
Keep the total seafood around 2 to 2.5 pounds. Add more of your favorites to balance it out.
In Conclusion
This baked seafood casserole delivers comfort, flavor, and weeknight-friendly ease in one pan. It’s flexible enough to match what you have, yet impressive enough for guests.
With a creamy, cheesy sauce and a crisp buttery topping, it’s the kind of dish that disappears fast. Keep this recipe in your rotation for those nights when you want something satisfying without the stress.