I love this recipe because it captures all the indulgent flavors of a seafood gratin without being complicated. The sauce is creamy and full of depth, the seafood stays tender, and the crispy breadcrumb topping adds the perfect contrast. It’s easy to prepare, adaptable to what I have on hand, and endlessly comforting—exactly the kind of dish I turn to when I want something special without hours in the kitchen.
Ingredients
(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)
1/2 lb lump crab meat, drained and picked over 1/2 lb small cooked shrimp, peeled and deveined 2 tablespoons unsalted butter 1/2 cup finely chopped onion 1/2 cup finely chopped celery 1/4 cup finely chopped red bell pepper 1 garlic clove, minced 1/4 cup all-purpose flour 1 cup milk 1/2 cup heavy cream 1/2 cup shredded mozzarella cheese 1/2 cup shredded cheddar cheese 1/4 teaspoon Old Bay seasoning Salt and black pepper, to taste 1/2 cup panko breadcrumbs 1 tablespoon olive oil 1 tablespoon chopped parsley (optional)
Directions
I preheat the oven to 375°F and lightly grease a 2-quart casserole dish.
In a large skillet, I melt the butter over medium heat and sauté the onion, celery, bell pepper, and garlic until everything is soft and fragrant.
I stir in the flour and cook it for about a minute, then slowly whisk in the milk and cream until the sauce thickens.
I remove the skillet from the heat and stir in the mozzarella, cheddar, Old Bay, plus salt and pepper.
I gently fold in the crab and shrimp, then transfer the mixture to the prepared casserole dish.
I mix the panko with the olive oil and sprinkle it evenly over the top.
I bake the casserole for 20–25 minutes, until the top is golden and the filling is bubbling.
I stir in a pinch of cayenne or red pepper flakes for extra heat.
I swap mozzarella for Monterey Jack when I want a meltier, slightly spicier flavor.
I add a splash of white wine to the sauce for a more elevated taste.
I use canned crab and thawed frozen shrimp when I need quicker prep.
I add sautéed mushrooms or spinach for more vegetables.
Storage/Reheating
I store leftovers in an airtight container in the refrigerator for up to 3 days. It reheats well in the oven at 325°F until warmed through, or in the microwave in short intervals. If the sauce thickens too much, I add a splash of milk or cream while reheating. I don’t freeze this casserole because the dairy base can separate.
FAQs
Can I use raw shrimp instead of cooked?
Yes, I use raw shrimp if I prefer, but I chop them small so they cook quickly in the oven.
What’s the best crab for this recipe?
I prefer lump crab for texture, but claw meat or canned crab also work well.
Can I make this casserole ahead of time?
Yes, I assemble it up to a day in advance, refrigerate it, and bake it when ready.
Why did my sauce turn grainy?
Using freshly shredded cheese and heating it gently helps keep the sauce smooth.
What sides pair well with this casserole?
I love serving it with rice, pasta, roasted vegetables, or crusty bread.
Conclusion
I love how this crab and shrimp casserole transforms simple seafood ingredients into a creamy, comforting bake that feels both nostalgic and elegant. The tender seafood, rich cheese sauce, and crispy topping make every bite irresistible. It’s the perfect dish for holidays, potlucks, or any evening when I want a warm, filling meal that feels a little special.
