If you love seafood and rich, comforting meals, this Baked Seafood Au Gratin is a recipe you’ll want to make again and again. Tender shrimp, flaky fish, and succulent scallops are baked in a creamy, flavorful sauce and topped with golden, bubbly cheese. Every bite is deliciously rich, making this dish perfect for a cozy family dinner or a special occasion.
The best part? This elegant seafood casserole is surprisingly easy to prepare at home. With simple ingredients, a smooth cream sauce, and a crispy golden topping, you can create a restaurant-style meal without spending hours in the kitchen.
Whether you’re planning a weekend dinner, entertaining guests, or simply craving a comforting seafood dish, this baked seafood au gratin is sure to impress.
Why You’ll Love This Baked Seafood Au Gratin
- Creamy and cheesy: A rich, velvety sauce coats every piece of seafood.
- Loaded with seafood: Shrimp, white fish, and scallops create a delicious combination of flavors and textures.
- Golden and bubbly: The cheese topping becomes beautifully melted and lightly browned in the oven.
- Easy to prepare: Simple ingredients and straightforward steps make this recipe approachable for home cooks.
- Perfect for special occasions: Serve it for family dinners, holidays, or an elegant seafood night.
Ingredients for Baked Seafood Au Gratin
For the Seafood
- 1 pound (450 g) mixed seafood, such as shrimp, white fish, and scallops
- 2 tablespoons unsalted butter
- 2 cloves garlic, minced
- 1 small shallot, finely chopped
- 1 tablespoon fresh lemon juice
- 1/2 teaspoon salt, or to taste
- 1/4 teaspoon black pepper
For the Creamy Sauce
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1 cup (240 ml) whole milk
- 1/2 cup (120 ml) heavy cream
- 1/2 teaspoon Dijon mustard
- 1/4 teaspoon paprika
- 1/4 cup (25 g) grated Parmesan cheese
- Salt and black pepper, to taste
For the Topping
- 3/4 cup (85 g) shredded Gruyère or mozzarella cheese
- 1/4 cup (25 g) grated Parmesan cheese
- 1/3 cup (35 g) breadcrumbs
- 1 tablespoon melted butter
- 1 tablespoon chopped fresh parsley
How to Make Baked Seafood Au Gratin
Step 1: Preheat the Oven
Preheat your oven to 400°F (200°C). Lightly grease a medium baking dish with butter or cooking spray.
Step 2: Prepare the Seafood
Pat the seafood dry with paper towels. Cut the white fish into bite-sized pieces and make sure the shrimp are peeled and deveined. Season lightly with salt, black pepper, and lemon juice.
Step 3: Sauté the Aromatics
Melt 2 tablespoons of butter in a large skillet over medium heat. Add the chopped shallot and minced garlic, cooking for 1–2 minutes until fragrant and softened.
Step 4: Make the Creamy Sauce
In a separate saucepan, melt 2 tablespoons of butter over medium heat. Whisk in the flour and cook for about 1 minute. Gradually pour in the milk and heavy cream, whisking continuously to prevent lumps.
Add the Dijon mustard, paprika, Parmesan cheese, salt, and black pepper. Simmer gently for 3–5 minutes, stirring until the sauce thickens. Remove from the heat.
Step 5: Combine the Seafood and Sauce
Add the seafood to the skillet with the garlic and shallot. Cook briefly for about 2 minutes, just until the outside begins to turn opaque. Transfer the seafood to the prepared baking dish and pour the creamy sauce over it. Gently stir to distribute the seafood evenly.
Step 6: Prepare the Golden Topping
In a small bowl, combine the shredded Gruyère or mozzarella, Parmesan, breadcrumbs, and melted butter. Sprinkle the mixture evenly over the seafood and sauce.
Step 7: Bake Until Golden
Bake uncovered for approximately 12–18 minutes, until the topping is golden and bubbling and the seafood is fully cooked. The center should reach a safe temperature of 145°F (63°C). If needed, broil for 1–2 minutes at the end, watching carefully to prevent burning.
Step 8: Garnish and Serve
Remove the dish from the oven and let it rest for 3–5 minutes. Sprinkle with fresh parsley and serve warm with lemon wedges.
Tips for the Best Seafood Au Gratin
- Choose seafood you enjoy: Shrimp, scallops, cod, haddock, and other firm white fish work well.
- Pat the seafood dry: Removing excess moisture helps prevent a watery sauce.
- Avoid overcooking: Seafood can become tough if baked for too long. Check doneness carefully.
- Use freshly grated cheese: It melts smoothly and gives the topping excellent flavor.
- Make the topping crispier: Combine breadcrumbs with melted butter before sprinkling them over the dish.
- Adjust the seasoning: A little extra lemon zest, paprika, or chopped parsley can brighten the creamy sauce.
What to Serve with Baked Seafood Au Gratin
This rich seafood dish pairs beautifully with simple sides that balance its creamy texture.
- Steamed vegetables: Broccoli, asparagus, or green beans add freshness.
- Garlic bread: Perfect for soaking up the creamy cheese sauce.
- Green salad: A crisp salad with lemon vinaigrette provides a refreshing contrast.
- Roasted potatoes: Golden potatoes make the meal even more satisfying.
- Steamed rice: A simple option for serving the extra sauce.
Can You Make Seafood Au Gratin Ahead of Time?
Yes. You can prepare the cream sauce and assemble the seafood and sauce in the baking dish ahead of time. Cover and refrigerate promptly, then add the breadcrumb and cheese topping just before baking.
For the best texture, bake soon after assembling and avoid leaving raw seafood at room temperature. If baking directly from the refrigerator, allow additional cooking time and check that the center reaches 145°F (63°C).
How to Store Leftovers
Allow leftovers to cool slightly, then transfer them to an airtight container and refrigerate within 2 hours. Store for up to 2 days for the best quality.
Reheat in an oven at 325°F (165°C) until heated through, taking care not to overcook the seafood. Freezing is not recommended because the cream sauce may separate and the seafood texture may change.
Frequently Asked Questions
What seafood is best for au gratin?
Shrimp, scallops, cod, haddock, and other firm white fish are excellent choices. A combination provides a variety of textures and flavors.
What does au gratin mean?
Au gratin refers to a dish topped with cheese, breadcrumbs, or a combination of both, then baked until the surface becomes golden and crisp.
Can I use frozen seafood?
Yes. Thaw frozen seafood completely in the refrigerator and pat it dry before cooking. This helps prevent excess liquid from thinning the sauce.
Which cheese melts best?
Gruyère gives the dish a rich, nutty flavor, while mozzarella creates a stretchy, mild topping. Parmesan adds a savory finish and helps the crust brown.
Final Thoughts
This Baked Seafood Au Gratin brings together tender seafood, a creamy garlic sauce, and a golden cheese-and-breadcrumb topping for a comforting meal that feels special without being complicated. Serve it straight from the oven with fresh parsley, lemon wedges, and your favorite side dishes.
If you’re looking for an easy way to turn everyday seafood into an impressive dinner, this creamy baked seafood au gratin deserves a place on your menu.
FAQ
Can I use frozen seafood for this baked seafood au gratin?
Yes, you can use frozen seafood, but thaw it completely in the refrigerator before starting your baked seafood au gratin. After thawing, drain the seafood thoroughly and pat it dry with paper towels. This prevents excess moisture from making your seafood casserole watery.
What type of fish works best in a homemade seafood au gratin?
Firm white fish varieties such as cod, haddock, or halibut work well in a homemade seafood au gratin. Cut the fish into even pieces alongside shrimp, scallops, or crabmeat. Everything then cooks at the same rate in your seafood bake.
How do I prevent my cheesy seafood bake from becoming watery?
The key to a rich cheesy seafood bake is removing excess water before assembling the dish. Pat your seafood completely dry, cook any added vegetables, and drain them thoroughly. Simmer your cream sauce until it properly coats the back of a spoon.
Can I prepare this seafood au gratin recipe ahead of time?
Absolutely. You can assemble this seafood au gratin recipe several hours ahead, cover it, and refrigerate it until baking. A chilled casserole may need a few extra baking minutes so the center becomes completely hot.
What temperature should my gourmet seafood bake reach when done?
Look for the sauce to bubble around the edges and the topping to turn crisp and golden brown. For food safety and best texture, ensure fish and shellfish reach 145°F, the recommended internal temperature, and are opaque and flaky.
What are the best side dishes to serve with an easy seafood au gratin?
Because this easy seafood au gratin has a rich, creamy sauce, it pairs well with bright, acidic, crisp sides. Serve it with fresh green salad in lemon vinaigrette, steamed green beans, roasted asparagus, or warm crusty French bread. These sides balance the heavy casserole.
