Creamy seafood gratin transforms ordinary weeknight dinners into something truly special, combining tender cod, shrimp, and scallops in a rich, bubbling cheese sauce. I’ve been making this comforting dish for over thirty years, and it never fails to bring smiles to the dinner table.
The finished creamy seafood gratin straight from Nonna Betty’s oven, showing the perfectly golden breadcrumb topping and bubbling edges
There’s something magical about watching a seafood gratin bubble away in the oven, filling your kitchen with the most incredible aroma. I still remember the first time my grandmother made this for Sunday dinner – the golden, crispy topping gave way to the creamiest, most luxurious seafood I’d ever tasted. What makes this recipe so special is how it brings together the best of both worlds: the elegance of fresh seafood with the comfort of a hearty, home-cooked meal. The secret lies in treating each piece of seafood gently and creating a sauce that’s rich enough to complement the delicate flavors without overwhelming them. Let’s get cooking!
Why You’ll Love This Creamy Seafood Gratin
This creamy seafood gratin has become one of my most requested recipes over the years, and for good reason. It’s rooted in classic French cooking techniques but adapted for the American home kitchen, making it accessible for cooks of all skill levels while still delivering restaurant-quality results.
Perfect for entertaining guests or celebrating special family occasions without spending all day in the kitchen
Uses everyday ingredients that you can find at any grocery store, making it budget-friendly despite feeling luxurious
Incredibly versatile – you can swap out seafood based on what’s fresh or on sale at your local market
The crispy breadcrumb topping provides the perfect textural contrast to the creamy, tender seafood underneath, similar to the layers in my Cheesy Au Gratin Potatoes.
Makes excellent leftovers that actually taste even better the next day as the flavors meld together
Can be assembled hours ahead of time, making dinner party hosting so much easier
This creamy seafood gratin is more than just a recipe – it’s a way to turn an ordinary evening into something memorable, bringing that special restaurant feeling right to your own dining room.
Ingredient Note List
Cod Fillet: Fresh cod provides a mild, flaky texture that absorbs all the creamy flavors beautifully without falling apart during baking.
Shrimp: I always recommend buying shrimp that’s already peeled and deveined to save time, and make sure they’re medium to large size so they don’t disappear in the dish.
Bay Scallops: These little gems add a sweet, delicate flavor that complements the other seafood perfectly – just make sure to pat them completely dry before using.
Butter: Real butter creates the base for our creamy sauce and adds that rich, indulgent flavor that makes this gratin so special.
All-Purpose Flour: This helps thicken our sauce to the perfect consistency – I always whisk it in slowly to avoid any lumps.
Milk and Heavy Cream: The combination gives us a sauce that’s rich but not too heavy, creating that perfect creamy texture we’re after.
Garlic Powder: I prefer garlic powder over fresh garlic here because it distributes more evenly throughout the sauce without overpowering the delicate seafood.
Parmesan Cheese: Freshly grated Parmesan melts much better than pre-shredded and gives the sauce a wonderful nutty, sharp flavor.
Breadcrumbs: These create that gorgeous golden topping that makes the gratin so visually appealing and adds a lovely crunch.
Fresh Parsley: A little fresh herb brightens up the whole dish and adds a pop of color to the finished gratin.
How to Cook Creamy Seafood Gratin
Step 1. I always start by preheating my oven to 375°F because you want it nice and hot when your gratin goes in for even cooking.
Step 2. Pat all your seafood completely dry with paper towels – this is crucial because any excess moisture will water down your beautiful creamy sauce.
Step 3. In my kitchen, I’ve learned that making a good roux is the secret to a smooth sauce, so melt your butter in a large skillet and whisk in the flour until it smells nutty but hasn’t browned.
Step 4. My grandmother always told me to add milk slowly while whisking constantly, and she was absolutely right – this prevents lumps and creates the silkiest sauce.
Step 5. I usually add all my seasonings at this point and let the sauce bubble gently for a few minutes to develop flavor and thicken properly.
Step 6. Turn off the heat before stirring in half the Parmesan cheese – the residual heat will melt it perfectly without making the sauce grainy.
Step 7. Gently fold the seafood into the sauce, being careful not to break apart the delicate cod pieces as you combine everything.
Step 8. Pour everything into your buttered baking dish and top with the breadcrumb mixture – I like to really cover the surface for maximum crispiness.
Step 9. Bake for 20-25 minutes until the top is golden brown and the edges are bubbling – if you want extra color, broil for just 1-2 minutes at the end.
How to Store & Reheat
I usually store leftover creamy seafood gratin in an airtight container in the refrigerator, where it stays fresh and delicious for up to 3 days. Make sure the dish has cooled completely before covering it to prevent condensation from making the topping soggy.
In my experience, this dish doesn’t freeze particularly well because seafood can become rubbery when frozen and thawed, so I recommend enjoying it fresh or within those first few days. However, if you do need to freeze portions, wrap them tightly in foil and use within one month.
For best results, I recommend reheating individual portions in the oven at 350°F for about 15 minutes, covered with foil to prevent the top from over-browning. You can also use the microwave for convenience – just cover with a damp paper towel and heat in 30-second intervals until warmed through.
Creamy Seafood Gratin
A rich, comforting seafood gratin made with cod, shrimp, and scallops in a creamy sauce topped with golden cheese and breadcrumbs. Ideal for special occasions or a hearty weekend meal.
Cut the cod into bite-sized pieces. Pat shrimp and scallops dry with paper towels.
In a large skillet, melt butter over medium heat. Whisk in the flour to form a roux and cook for 2 minutes until it smells nutty.
Gradually whisk in the milk and heavy cream until smooth and thickened. Stir in garlic powder, onion powder, paprika, cayenne (if using), salt, and black pepper.
Remove from heat and stir in half of the Parmesan cheese until melted and smooth.
In a large bowl, toss cod, shrimp, and scallops with lemon juice and a pinch of salt. Gently fold into the cheese sauce.
In a small bowl, mix breadcrumbs, remaining Parmesan, olive oil, and parsley. Sprinkle evenly over the top.
Bake for 20–25 minutes, until the top is golden and sauce is bubbling. For extra crispiness, broil for 1–2 minutes at the end.
Let the gratin rest for 5 minutes before serving. Enjoy!
Notes
Use well-dried seafood to prevent watery sauce. Prepare ahead and bake just before serving. Swap in crab or lobster for variety. Broil briefly at the end for a golden crust.
What to Serve with Creamy Seafood Gratin
Crusty French Bread: The crispy exterior and soft interior of good French bread is perfect for soaking up every drop of that creamy sauce – it’s practically essential with this dish.
Simple Mixed Green Salad: A light salad dressed with lemon vinaigrette cuts through the richness beautifully and adds fresh, crisp texture to balance the meal.
Roasted Asparagus: The slight char and natural sweetness of roasted asparagus pairs wonderfully with seafood and adds elegant color to your plate.
Garlic Mashed Potatoes: While the gratin is rich on its own, creamy mashed potatoes make this into an incredibly satisfying, restaurant-style meal.
Steamed Broccoli: The bright green color and fresh flavor of perfectly steamed broccoli provides a nutritious contrast that my family always appreciates.
Crisp White Wine: Though not a side dish, a chilled Sauvignon Blanc or Pinot Grigio complements the creamy seafood flavors perfectly for special occasions.
FAQs
Can I use frozen seafood for this creamy seafood gratin?
I recommend thawing frozen seafood completely and patting it very dry before using – the key is removing as much moisture as possible so your sauce stays creamy and doesn’t become watery.
How do I prevent the seafood from becoming rubbery?
The secret is not to overcook it – seafood continues cooking in the oven, so it should still be slightly underdone when you fold it into the sauce, and watch your baking time carefully.
Can I make this seafood gratin ahead of time?
Absolutely! I often assemble the entire dish up to 24 hours ahead, cover it tightly with plastic wrap, and refrigerate until ready to bake – just add 5 extra minutes to the cooking time.
What’s the best way to tell when the gratin is done?
Look for a golden brown top and sauce that’s bubbling around the edges – if you insert a knife into the center, the seafood should be opaque and flake easily when tested.
