Seafood gratin is a cozy, slightly indulgent casserole of shrimp and scallops baked in a creamy, cheesy sauce until golden and bubbly. It’s the kind of dish I reach for when I want something impressive but unfussy — perfect for a weeknight that needs a little celebration or a simple holiday starter. The seafood cooks quickly, the sauce comes together in a single bowl, and the result feels restaurant-worthy without the fuss. If you plan a relaxed dinner, pair it with a bold cocktail like this Grateful Dead drink for a fun contrast: Grateful Dead Drink.
Why you’ll love this dish
This gratin balances rich, creamy comfort with bright seafood flavors. The lemon juice keeps the cream from feeling too heavy and the cheese adds savory depth and a beautiful crust. It’s fast to cook — most active time is just sautéing the seafood and whisking the sauce — but it reads fancy on the table.
"Made this for guests and got compliments all night — rich, simple, and reliably elegant." — a reader-style note
Great occasions: weeknight date night, small dinner parties, holiday seafood course, or a make-ahead entrée when you want to minimize time spent at the stove.
The cooking process explained
Before you dive in, here’s the short play-by-play so you know what to expect:
- Sauté garlic in butter to build a fragrant base.
- Quickly cook shrimp and scallops until just opaque; they’ll finish in the oven.
- Whisk cream, cheese, and lemon for a silky sauce.
- Combine seafood and sauce, bake until bubbling and golden.
- Rest briefly, then serve with bread or pasta to sop up the sauce.
This overview helps you work confidently and avoid overcooking the seafood.
What you’ll need
- 1 lb shrimp, peeled and deveined (medium or large)
- 1 lb scallops (dry-packed preferred; patted dry)
- 2 cups heavy cream
- 1 cup grated cheese (Gruyère or Parmesan work well)
- 2 tbsp butter
- 2 cloves garlic, minced
- 1 tsp lemon juice
- Salt and freshly ground black pepper to taste
- Fresh bread or cooked pasta, for serving
Substitution notes: use half-and-half plus a tablespoon of flour if you want a slightly lighter sauce (texture will differ). For a nuttier top, swap half the grated cheese for aged Parmesan. If you want a sweet finish later, serve dessert like this dessert lasagna.
Step-by-step instructions
- Preheat the oven to 375°F (190°C). Grease a medium baking dish with butter or nonstick spray.
- In a large skillet, melt the butter over medium heat. Add the minced garlic and cook 30–60 seconds until fragrant — don’t let it brown.
- Add the shrimp and scallops to the skillet. Sear 1–2 minutes per side until they turn just opaque. Remove from heat; they’ll finish cooking in the oven.
- In a bowl, whisk together the heavy cream, grated cheese, lemon juice, and a pinch each of salt and pepper until smooth. Taste and adjust seasoning.
- Fold the seared seafood into the cream mixture so everything is evenly coated. Pour the mixture into the prepared baking dish.
- Bake 20–25 minutes until the gratin is bubbling and the top is golden. If you want extra color, broil for 1–2 minutes watching carefully so it doesn’t burn.
- Let rest 3–5 minutes before serving. Spoon over fresh bread or toss with hot pasta to serve.
Short, direct steps make it easy to follow while you’re cooking.
Best ways to enjoy it
Serve the gratin straight from the oven with:
- Thick slices of crusty bread to soak up the sauce.
- Buttered tagliatelle or linguine tossed with a little olive oil, topped with spoonfuls of gratin.
- A crisp green salad with vinaigrette to cut the richness.
For a backyard or casual spread, add a sweet-hot contrast (try a smoky condiment or tangy slaw). If you’re planning a party menu, a smoky BBQ starter might be on the playlist — for inspiration, see this quick barbecue sauce idea: Barbecue Sauce From Jelly.
Storage and reheating tips
- Refrigerator: Cool to room temperature, cover tightly, and refrigerate up to 3 days.
- Freezing: The gratin can be frozen for up to 1 month. Freeze before final baking (cover tightly) and bake from frozen, adding extra time until heated through. Note: texture of seafood may change slightly after freezing.
- Reheating: Reheat individual portions in a 325°F oven until warmed through (15–20 minutes). Avoid microwaving large portions — it can make the seafood rubbery. If microwaving small servings, use short intervals and a lower power setting.
Food safety: always cool cooked seafood promptly and store within two hours of cooking.
Pro chef tips
- Pat seafood dry before sautéing — moisture prevents a good sear.
- Don’t overcook the shrimp and scallops in the skillet. They should still be slightly underdone when you transfer to the baking dish. They’ll finish in the oven without getting tough.
- Use a high-melting cheese like Gruyère for a meltier crust; Parmesan adds sharpness. A 50/50 blend is a safe, flavorful choice.
- For a golden top, mix a tablespoon of melted butter with 1/4 cup panko breadcrumbs and sprinkle before baking, or broil briefly at the end.
- If you like a brighter sauce, stir in a splash of dry white wine into the cream mixture before baking.
Also consider making individual gratins in ramekins for elegant single servings.
Creative twists
- Add diced mushrooms and shallots sautéed first for an earthy variation.
- Swap seafood for a vegetarian version: use king oyster mushrooms and artichoke hearts.
- Add a tablespoon of Dijon mustard to the cream for tang.
- Make it “au gratin” with a breadcrumb-cheese crust or keep it smooth and cheesy without crumbs.
- To suit a celebration-themed menu, prepare mini portions and pair with small themed desserts like these gender-reveal cupcakes.
Common questions
Q: How long does prep and total time take?
A: Prep is about 15–20 minutes. Baking is 20–25 minutes, so total time is roughly 40–50 minutes.
Q: Can I use frozen seafood?
A: Yes. Thaw overnight in the fridge and pat dry before cooking. Do not refreeze thawed seafood once cooked.
Q: Is this safe for kids and pregnant people?
A: The recipe uses fully cooked seafood; ensure shrimp and scallops reach an opaque, firm texture. Pregnant people should confirm the seafood was handled and frozen properly before consumption — when in doubt, consult a healthcare provider.
Q: Can I make this ahead?
A: You can assemble it, cover, and refrigerate up to 24 hours before baking. Add a few extra minutes to the bake time if chilled.
Q: What cheese is best?
A: Gruyère melts beautifully and adds nuttiness. Parmesan adds savory saltiness. A blend is ideal.
Conclusion
If you want a classic French-inspired gratin to add to your repertoire, you’ll find helpful variations and a slightly different technique in this traditional take: L’Irrésistible Gratin de Fruits de Mer. For a historical perspective and a tried-and-true version, Julia Child’s approach is worth reading alongside your own experiments: Gratin Aux Fruits De Mer (Julia Child) Recipe.
Seafood Gratin
Ingredients
Seafood
- 1 lb shrimp, peeled and deveined (medium or large)
- 1 lb scallops (dry-packed preferred; patted dry)
Sauce
- 2 cups heavy cream
- 1 cup grated cheese (Gruyère or Parmesan work well)
- 2 tbsp butter
- 2 cloves garlic, minced
- 1 tsp lemon juice
- Salt and freshly ground black pepper to taste
For Serving
- Fresh bread or cooked pasta For serving
Instructions
Preparation
- Preheat the oven to 375°F (190°C). Grease a medium baking dish with butter or nonstick spray.
- In a large skillet, melt the butter over medium heat. Add the minced garlic and cook for 30–60 seconds until fragrant — don’t let it brown.
- Add the shrimp and scallops to the skillet. Sear for 1–2 minutes per side until they turn just opaque. Remove from heat; they’ll finish cooking in the oven.
- In a bowl, whisk together the heavy cream, grated cheese, lemon juice, and a pinch of salt and pepper until smooth. Taste and adjust seasoning.
- Fold the seared seafood into the cream mixture so everything is evenly coated. Pour the mixture into the prepared baking dish.
Baking
- Bake for 20–25 minutes until the gratin is bubbling and the top is golden. If you want extra color, broil for 1–2 minutes watching carefully so it doesn’t burn.
- Let rest for 3–5 minutes before serving. Spoon over fresh bread or toss with hot pasta to serve.