Creamy Seafood Gratin with Scallops Shrimp

Creamy Seafood Gratin with Scallops Shrimp tastes rich, buttery, and cheesy with sweet bites of tender seafood under a golden crust. It suits cozy date nights, small dinner parties, or a “treat yourself” weeknight since it comes together in about 45 minutes. I first made a version of this in my tiny studio kitchen in Boston and nearly set off the smoke alarm, so you can trust I tested this one a lot.

Why Creamy Seafood Gratin with Scallops Shrimp Is Worth It

This seafood gratin feels fancy but stays surprisingly simple and weeknight friendly. You get restaurant-level flavor with basic grocery store ingredients and one main baking dish.

The scallops and shrimp cook gently in the creamy sauce, so they stay juicy and tender. The crunchy, cheesy topping adds contrast and makes every bite feel special.

“This Creamy Seafood Gratin with Scallops Shrimp tastes like a cozy coastal restaurant special that somehow landed in your own oven. ★★★★★”

Ingredients You Need

Seafood

• Large sea scallops, patted dry
• Large shrimp, peeled and deveined, tails off or on
• Fresh lemon, for zest and juice over the seafood
• Kosher salt and freshly ground black pepper

Use fresh seafood when possible. If you use frozen scallops or shrimp, thaw them fully in the fridge and pat them very dry so the gratin does not turn watery.

Creamy sauce base

• Unsalted butter
• Olive oil
• Shallots, finely minced
• Garlic, finely minced
• All purpose flour
• Whole milk or half and half
• Heavy cream
• Dijon mustard
• Fresh thyme leaves or dried thyme
• Smoked or sweet paprika
• Fresh parsley, chopped

Whole milk and cream give the best texture. You can use all half and half in a pinch, but the sauce will taste a bit lighter.

Cheeses

• Gruyère cheese, shredded (melts smooth and nutty)
• Parmesan cheese, finely grated
• Optional: a little mozzarella for extra stretch

You can use Swiss cheese instead of Gruyère if that fits your budget better. Use real Parmesan, not the shelf stable shaker, for best flavor.

Crunchy topping

• Panko breadcrumbs
• Melted butter
• Extra Parmesan
• Pinch of salt and pepper

Panko gives a lighter, crispier crust than regular breadcrumbs. If you only have regular crumbs, use those and add a bit more melted butter.

Pantry shortcuts and flavor boosters

• Seafood stock or clam juice, optional but tasty
• Old Bay or your favorite seafood seasoning blend
• Lemon zest for brightness
• A pinch of red pepper flakes for gentle heat

Seafood stock or clam juice deepens the flavor of the sauce. If you do not have it, just use more milk and season the sauce well.

Equipment list

• 9 by 13 inch baking dish or similar casserole dish
• Medium saucepan
• Large skillet
• Whisk
• Cutting board and sharp knife
• Microplane or fine grater for zest and Parmesan
• Measuring cups and spoons

Quick Tips & substitutions

• Pat scallops and shrimp very dry so they brown slightly and do not water down the sauce.
• Use small bay scallops if you find them on sale and reduce the bake time by a few minutes.
• Swap Gruyère with Swiss or provolone if you want a milder flavor.
• Use all milk instead of cream for a lighter gratin and reduce the flour slightly so the sauce does not turn too thick.
• Add a handful of frozen peas or corn straight from the freezer into the sauce for extra color and sweetness.
• Use gluten free panko and a gluten free flour blend to keep the gratin gluten free.
• Season the seafood lightly before it hits the dish so the flavor goes all the way through.
• Let the gratin rest 5 to 10 minutes after baking so the sauce thickens and slices cleanly.

How to Make Creamy Seafood Gratin with Scallops Shrimp

Prep the seafood and baking dish

1. Preheat your oven to 400°F and grease your baking dish with butter or olive oil.
2. Pat the scallops and shrimp very dry with paper towels.
3. Season them with salt, pepper, a little paprika, and a light sprinkle of lemon zest.
4. Arrange the scallops and shrimp in a single layer in the baking dish and keep it in the fridge while you make the sauce.

Build the creamy sauce

1. Heat a mix of butter and olive oil in a skillet over medium heat.
2. Add minced shallots and cook until they turn soft and translucent, about 3 minutes.
3. Stir in the garlic and cook 30 seconds, so it smells fragrant but not browned.
4. Sprinkle the flour over the shallots and garlic and stir constantly for 1 to 2 minutes to form a smooth paste.

Add liquids and seasonings

1. Slowly whisk in the milk and cream, a little at a time, so the mixture stays smooth.
2. Add a splash of seafood stock or clam juice if you use it.
3. Stir in Dijon mustard, thyme, paprika, salt, pepper, and a pinch of red pepper flakes.
4. Simmer the sauce for 3 to 5 minutes, while you stir often, until it thickens to a gravy like consistency.

Add the cheese

1. Turn the heat to low and add shredded Gruyère and some Parmesan.
2. Stir until the cheese melts and the sauce turns silky and thick.
3. Taste and adjust the seasoning with more salt, pepper, or lemon zest.
4. Remove the pan from the heat and stir in chopped parsley.

Assemble the gratin

1. Take the baking dish with scallops and shrimp out of the fridge.
2. Pour the hot creamy cheese sauce evenly over the seafood, so it tucks into all the gaps.
3. Gently shake the dish to help the sauce settle without moving the seafood too much.
4. You want the sauce to almost cover the seafood but still show a few pieces on top.

Mix the crunchy topping

1. In a small bowl, mix panko, grated Parmesan, salt, pepper, and melted butter.
2. Toss with a fork until the crumbs look evenly coated and slightly clumpy.
3. Sprinkle the crumb mixture evenly over the top of the sauced seafood.
4. Add a final light dusting of paprika for color if you like.

Bake to golden perfection

1. Place the baking dish on a sheet pan to catch any drips.
2. Bake at 400°F for 15 to 18 minutes, until the topping turns golden and the sauce bubbles around the edges.
3. If the top needs more color, switch the oven to broil for 1 to 2 minutes and watch closely.
4. Pull the gratin out and let it rest 5 to 10 minutes so the sauce thickens and the seafood finishes gently.

Finish and serve

1. Squeeze a little fresh lemon juice over the top right before serving.
2. Sprinkle more chopped parsley or chives for a fresh pop of color.
3. Serve big spoonfuls of the Creamy Seafood Gratin with Scallops Shrimp over rice, potatoes, or crusty bread.
4. Enjoy while the top stays crisp and the center tastes hot and creamy.

Recipe Variations

• Gluten free: Use gluten free panko and a 1 to 1 gluten free flour blend in the sauce.
• Lower carb: Skip the flour and thicken the sauce with a little cream cheese or a small amount of xanthan gum.
• Extra seafood: Add chunks of firm white fish or crab meat along with the scallops and shrimp.
• Veggie loaded: Stir in blanched broccoli florets, spinach, or sautéed mushrooms before you add the sauce to the baking dish.
• Lighter dairy: Use all half and half and reduce the cheese by one third for a lighter but still creamy version.
• Spicy: Add more red pepper flakes or a spoon of your favorite chili paste to the sauce.
• Herb twist: Swap thyme for tarragon or dill for a different flavor profile that still loves seafood.

Ways to Serve Creamy Seafood Gratin with Scallops Shrimp

• Spoon over fluffy white rice, brown rice, or wild rice.
• Serve with garlic mashed potatoes or simple boiled baby potatoes.
• Pair with buttered noodles or plain pasta.
• Add a crisp green salad with lemony dressing on the side.
• Scoop with warm crusty bread or toasted baguette slices.
• Serve with roasted asparagus, green beans, or a medley of roasted vegetables.

Storage Success

Let the Creamy Seafood Gratin with Scallops Shrimp cool to room temperature, then cover the dish tightly and store it in the fridge for up to 2 days. Reheat portions gently in a 325°F oven until hot, so the seafood stays tender and the sauce does not split. You can reheat in the microwave in short bursts, but stir often and stop as soon as it turns hot. I do not suggest freezing this gratin, since the cream sauce can separate and the scallops and shrimp can turn rubbery after thawing.

Creamy Seafood Gratin with Scallops and Shrimp

Creamy Seafood Gratin with Scallops and Shrimp is a rich, comforting baked dish with tender seafood in a velvety cream sauce, topped with a golden, cheesy crust.

Pin This Recipe Share on Facebook

Prep Time 20 minutes mins

Cook Time 25 minutes mins

Total Time 45 minutes mins

Servings: 4

Course: Dinner

Cuisine: American

Ingredients

  

• 8 ounces large sea scallops, patted dry
• 8 ounces large shrimp, peeled and deveined
• 2 tablespoons unsalted butter
• 1 tablespoon olive oil
• 2 cloves garlic, minced
• 1 small shallot, finely chopped
• 1/2 cup dry white wine
• 3/4 cup heavy cream
• 1/2 cup whole milk
• 1 tablespoon all-purpose flour
• 1/4 cup grated Parmesan cheese
• 1/3 cup panko breadcrumbs
• 2 tablespoons grated Gruyère or Swiss cheese
• 1 tablespoon fresh parsley, chopped
• 1/4 teaspoon paprika
• 1/4 teaspoon salt, or to taste
• 1/4 teaspoon black pepper, or to taste
• 1 teaspoon lemon juice
• 1 tablespoon butter, melted (for topping)

Instructions

 

1. Preheat the oven to 400°F (200°C). Lightly butter or oil a shallow baking dish or 4 individual gratin dishes.
2. Pat the scallops and shrimp dry with paper towels. Season lightly with a pinch of salt and black pepper.
3. Heat the olive oil and 2 tablespoons butter in a skillet over medium heat. Add the scallops and shrimp and cook 1–2 minutes per side, just until they start to turn opaque. Transfer the seafood to the prepared baking dish; reserve any juices in the pan.
4. In the same skillet, add the shallot and cook over medium heat for 2–3 minutes until softened. Add the garlic and cook 30 seconds until fragrant.
5. Sprinkle in the flour and cook, stirring constantly, for 1 minute to form a roux.
6. Slowly pour in the white wine (if using), scraping up any browned bits, and simmer for 1–2 minutes. Gradually whisk in the cream and milk, stirring until smooth and slightly thickened, 3–4 minutes.
7. Stir in the Parmesan cheese, paprika, salt, and black pepper. Add lemon juice if desired. Taste and adjust seasoning as needed.
8. Pour the creamy sauce evenly over the scallops and shrimp in the baking dish.
9. In a small bowl, mix the panko breadcrumbs, Gruyère cheese, parsley, and melted butter until combined. Sprinkle this mixture evenly over the top of the gratin.
10. Bake for 12–15 minutes, or until the topping is golden brown and the sauce is bubbling around the edges.
11. Let the gratin rest for 5 minutes before serving. Serve hot with crusty bread, rice, or a simple green salad.

Notes

Nutrition Information
Approximate per serving (1/4 of recipe): 420 calories; fat 28 g; saturated fat 15 g; carbohydrates 14 g; fiber 0 g; sugars 3 g; protein 24 g; sodium 520 mg. Values will vary based on brands, add-ins, and portion size.