Creamy Seafood Gratin with Scallops Shrimp tastes rich, buttery, and slightly sweet from the tender seafood tucked into a cheesy, golden crust. It suits seafood lovers who want a cozy, restaurant-level dinner at home in about 50 minutes from start to finish. I first made a version of this on a Tuesday when I felt fancy in sweatpants, and it has stayed in my regular rotation ever since.
Why You Should Try This Creamy Seafood Gratin with Scallops Shrimp
This Creamy Seafood Gratin with Scallops Shrimp gives you all the flavor of a special-occasion restaurant dish without the white tablecloth. The scallops stay tender, the shrimp stay juicy, and the creamy sauce hugs everything under a blanket of crisp, cheesy breadcrumbs.
You can prep it ahead, slide it into the oven when guests arrive, and pull out bubbling, golden perfection. It works for date night, holidays, or a solo treat when you want something indulgent and comforting.
“This Creamy Seafood Gratin with Scallops Shrimp tastes like a fancy coastal restaurant baked it just for you, only you made it in your own kitchen. ★★★★★”
Ingredients You’ll Need
Seafood
- Large sea scallops
- Pat them very dry so they brown and do not steam.
- Use dry-packed scallops if possible; they taste sweeter and sear better.
- Large shrimp, peeled and deveined
- Use 16–20 count or similar so they do not overcook too fast.
- Frozen shrimp work great; thaw in the fridge overnight or in cold water.
- Optional: small handful of white fish chunks (like cod or halibut)
Vegetables & Aromatics
- 1 small yellow onion, finely diced
- 2 cloves garlic, minced
- 1 small leek, white and light green parts only, thinly sliced (optional but lovely)
- 1 rib celery, finely diced
- 1 tablespoon fresh parsley, chopped
- 1 teaspoon fresh thyme leaves or 1/2 teaspoon dried thyme
These vegetables build flavor in the base and add a little texture so the gratin feels hearty, not just creamy.
Dairy & Sauce Base
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 1 1/2 cups whole milk
- 1/2 cup heavy cream
- 1/2 cup seafood stock or low-sodium chicken broth
- 1 teaspoon Dijon mustard
- 1/4 teaspoon smoked paprika or sweet paprika
- 1/4 teaspoon cayenne pepper (optional, for a gentle kick)
- Salt and black pepper to taste
Use whole milk for the best texture. If you only have 2% milk, add an extra tablespoon of butter to keep the sauce silky.
Cheese & Topping
- 1 cup grated Gruyère cheese
- Melts beautifully and gives a nutty flavor.
- Substitute with Swiss cheese if Gruyère costs too much or you cannot find it.
- 1/2 cup grated Parmesan cheese
- 1 cup panko breadcrumbs
- 2 tablespoons melted butter
- 1 tablespoon chopped fresh parsley or chives for garnish
Panko gives the topping extra crunch. If you only have regular breadcrumbs, use them and toast the top under the broiler at the end for extra color.
Pantry Shortcuts & Brand Notes
- Use jarred minced garlic if you feel tired or short on time; just do not go overboard because it tastes stronger.
- Boxed seafood stock or clam juice works when you do not have homemade stock.
- Pre-shredded cheese works in a pinch, but I prefer to grate from a block because it melts smoother and tastes cleaner.
Equipment List
- Large skillet or sauté pan
- Medium saucepan
- Whisk
- Cutting board and sharp knife
- Mixing bowls
- 1 1/2 to 2 quart baking dish (or individual gratin dishes)
- Measuring cups and spoons
- Oven and broiler
Tips & Tricks
- Pat scallops and shrimp very dry with paper towels so they brown and do not water down the sauce.
- Salt the seafood lightly before cooking, not after baking, so the seasoning goes inside each bite.
- Sear scallops quickly over medium-high heat until they get light color; keep the centers slightly under so they finish in the oven.
- Use room-temperature milk and cream for the sauce when possible to avoid lumps.
- Whisk the roux and milk slowly and constantly so the sauce stays smooth and creamy.
- Taste the sauce before you pour it over the seafood and adjust salt, pepper, and mustard.
- Keep the sauce a bit thicker than soup; it should coat the back of a spoon and leave a line when you drag your finger through it.
- Do not overfill the baking dish; leave a little space at the top so the gratin can bubble without spilling.
- Mix panko with melted butter and cheese right before topping so it stays crisp.
- Bake until the top turns deep golden and the edges bubble; pull it out before the seafood overcooks.
- Let the gratin rest 5 to 10 minutes before serving so the sauce thickens slightly and does not run all over the plate.
- Use individual ramekins if you want restaurant-style presentation and easier portion control.
How to Make Creamy Seafood Gratin with Scallops Shrimp
1: Prep the seafood and aromatics
Peel and devein the shrimp if needed, then pat them dry and place them in a bowl. Pat the scallops dry on all sides and trim any tough side muscle. Season both lightly with salt and pepper and set them in the fridge while you prep the vegetables.
Dice the onion and celery, slice the leek, and mince the garlic. Chop the parsley and thyme and keep them nearby. Preheat your oven to 400°F and butter your baking dish.
2: Sear the scallops and shrimp
Heat a tablespoon of oil in a large skillet over medium-high heat. Add the scallops in a single layer and sear 1 to 2 minutes per side until they show light golden color. Pull them out to a plate; they should still feel slightly soft in the center.
Add the shrimp to the same pan and cook 1 to 2 minutes, just until they start to turn pink. Transfer them to the plate with the scallops. You only want partial cooking at this stage so they stay tender after baking.
3: Sauté veggies and aromatics
Lower the heat to medium and add a tablespoon of butter to the same skillet. Add the onion, celery, and leek with a pinch of salt and cook 5 to 7 minutes until they soften and turn translucent. Stir in the garlic and cook about 30 seconds until it smells fragrant.
Sprinkle in the thyme and parsley and stir. Turn off the heat and let the vegetables sit while you make the sauce. They will finish softening in the oven.
4: Make the creamy sauce
In a medium saucepan, melt 3 tablespoons of butter over medium heat. Whisk in the flour and cook 1 to 2 minutes, whisking constantly, until the mixture looks smooth and slightly foamy. Slowly pour in the milk while you whisk so no lumps form.
Add the cream and seafood stock and keep whisking until the sauce thickens and coats the back of a spoon. Stir in Dijon mustard, paprika, cayenne if you use it, and a small pinch of salt and pepper. Turn off the heat and stir in half of the Gruyère and half of the Parmesan until they melt into the sauce.
5: Combine seafood, veggies, and sauce
Spread the sautéed vegetables evenly in the bottom of your buttered baking dish. Arrange the scallops and shrimp over the vegetables so you get a mix in every scoop. Pour the hot cheese sauce over everything and gently shake the dish to help it settle into the gaps.
Sprinkle the remaining Gruyère and Parmesan over the top. You want a thin, even layer so the topping browns nicely. If the sauce looks very close to the rim, place the dish on a sheet pan to catch any drips.
6: Add the crunchy topping
In a small bowl, mix the panko breadcrumbs with the melted butter and a pinch of salt and pepper. Toss until every crumb looks lightly coated. Sprinkle this mixture evenly over the cheesy surface of the gratin.
Press the topping very gently with your fingers so it sticks to the sauce. Do not pack it down too firmly or it will turn dense instead of crisp. Sprinkle a bit more Parmesan on top if you feel extra cheesy.
7: Bake until golden and bubbly
Place the baking dish in the preheated 400°F oven. Bake 15 to 20 minutes until the edges bubble and the top turns golden brown. If the top needs more color, switch to broil for 1 to 2 minutes and watch closely so it does not burn.
Pull the gratin out and let it rest 5 to 10 minutes. Scatter fresh parsley or chives over the top for color. Serve hot while the sauce stays creamy and the topping stays crisp.
What to Serve with Creamy Seafood Gratin
This Creamy Seafood Gratin with Scallops Shrimp tastes rich, so pair it with something fresh and simple. A crisp green salad with lemony vinaigrette cuts through the cream and balances the flavors. Steamed or roasted vegetables like asparagus, green beans, or broccoli work well and keep the plate colorful.
You can spoon the gratin over fluffy white rice, buttered noodles, or crusty bread to soak up the sauce. Sparkling water with citrus slices or a light iced tea keeps the meal bright without overpowering the seafood.
Storage Options
- Cool leftovers to room temperature, then cover tightly and store in the fridge for up to 2 days.
- Reheat in a 325°F oven, covered with foil, for 15 to 20 minutes until hot in the center, then uncover for a few minutes to crisp the topping again.
- Avoid the microwave if possible, since it can overcook the shrimp and scallops and turn them rubbery.
- Freeze only if needed: portion into airtight containers, freeze up to 1 month, then thaw in the fridge overnight and reheat gently in the oven; expect a slightly looser sauce after freezing.
Creamy Seafood Gratin with Scallops and Shrimp
Ingredients
Instructions
- Preheat the oven to 400°F (200°C). Lightly butter a shallow baking dish or individual gratin dishes.
- Pat the scallops and shrimp dry with paper towels and season lightly with a pinch of salt and pepper.
- In a large skillet, heat the olive oil and 1 tablespoon of butter over medium-high heat. Sear the scallops and shrimp for 1–2 minutes per side until just opaque on the outside. Transfer to the prepared baking dish and spread in an even layer.
- Reduce the heat to medium. Add the remaining 1 tablespoon butter to the skillet, then add the garlic and cook for about 30 seconds until fragrant.
- Sprinkle in the flour and cook, stirring constantly, for 1 minute to form a light roux.
- Slowly pour in the white wine (if using), stirring and scraping up any browned bits. Let it simmer for 1–2 minutes until slightly reduced.
- Whisk in the heavy cream and milk. Cook, stirring frequently, until the sauce thickens enough to coat the back of a spoon, 3–5 minutes.
- Stir in the Parmesan, Gruyère, salt, pepper, paprika, and lemon juice until the cheeses melt and the sauce is smooth. Adjust seasoning to taste.
- Pour the creamy sauce evenly over the scallops and shrimp in the baking dish.
- In a small bowl, combine the panko breadcrumbs with the melted butter and parsley (if using). Sprinkle the mixture evenly over the top of the gratin.
- Bake for 12–15 minutes, or until the topping is golden brown and the sauce is bubbling around the edges.
- Let the gratin rest for 5 minutes before serving to allow the sauce to slightly thicken. Serve hot, optionally with crusty bread, rice, or a green salad.
Notes
Approximate per serving (4 servings): 520 calories; fat 36 g; saturated fat 20 g; carbohydrates 13 g; fiber 0 g; sugars 4 g; protein 33 g; sodium 710 mg. Values are estimates and will vary based on specific ingredient brands, optional wine use, and portion size.