Name: Seafood Gratin with Mushrooms
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: American
Ingredients: 1 lb mixed seafood (shrimp, scallops, and white fish); 1 tablespoon olive oil; 1 small onion, chopped; 2 cloves garlic, minced; 1 cup mushrooms, sliced; 1/2 cup heavy cream; 1/2 cup grated Parmesan cheese; 1/2 cup shredded mozzarella cheese; 1/4 cup breadcrumbs; 2 tablespoons butter; Salt and pepper to taste; Fresh parsley, chopped for garnish

Jump to Recipe·Print Recipe

This Seafood Gratin with Mushrooms is a creamy, oven-baked dish packed with succulent seafood, earthy mushrooms, and a savory cheese topping that turns irresistibly golden and bubbly. It’s comfort food with a touch of elegance, perfect for impressing guests or simply treating myself to something special on a weeknight.

Ingredients

(Tip: You'll find the full list of ingredients and measurements in the recipe card below.)

1 lb mixed seafood (shrimp, scallops, and white fish)

1 tablespoon olive oil

1 small onion, chopped

2 cloves garlic, minced

1 cup mushrooms, sliced

½ cup heavy cream

½ cup grated Parmesan cheese

½ cup shredded mozzarella cheese

¼ cup breadcrumbs

2 tablespoons butter

Salt and pepper to taste

Fresh parsley, chopped for garnish

Directions

I preheat the oven to 375°F (190°C).

I heat the olive oil in a skillet over medium heat, then add the chopped onion and garlic, sautéing for 2-3 minutes until they soften.

I toss in the sliced mushrooms and cook for another 3-4 minutes until they release moisture and become tender.

I stir in the mixed seafood and let it cook for 2-3 minutes until just opaque.

I pour in the heavy cream, stir to combine, and let it simmer for a few minutes until the sauce slightly thickens. I season it with salt and pepper.

I transfer everything into a greased baking dish.

In a small bowl, I mix together the Parmesan, mozzarella, and breadcrumbs, then sprinkle the mixture over the seafood.

I dot the top with butter and bake the gratin for 20-25 minutes until golden and bubbling.

I garnish with fresh parsley before serving hot.

Servings and Timing

This recipe serves 4 people.

Prep time: 10 minutes

Cook time: 30 minutes

Total time: 40 minutes

Calories per serving: Approximately 350 kcal

Variations

I sometimes add a splash of white wine to the cream sauce for extra depth.

Swapping mozzarella with Gruyère or Fontina gives it a nuttier, richer flavor.

If I don’t have scallops, I just double the shrimp or use chunks of salmon.

For a lighter version, I use half-and-half instead of heavy cream.

I’ve even tossed in a handful of spinach before baking for a bit of green and extra nutrition.

Storage/Reheating

I store leftovers in an airtight container in the fridge for up to 2 days.
To reheat, I use the oven at 350°F (175°C) for about 15 minutes or until warmed through. Microwaving works too, but I cover it with a damp paper towel to keep the seafood moist. I avoid freezing since the creamy sauce and seafood texture don’t hold up well after thawing.

FAQs

How do I know when the seafood is cooked through?

I look for the seafood to turn opaque and slightly firm. It finishes cooking in the oven, so I only partially cook it on the stovetop to avoid overcooking.

Can I use frozen seafood?

Yes, I just make sure to thaw it completely and pat it dry to avoid excess water in the dish.

What type of white fish works best?

I like using cod, haddock, or tilapia—any mild, flaky white fish will do the job well.

Can I make this dish ahead of time?

Absolutely. I prepare everything up to the baking step, cover it, and refrigerate for a few hours. When ready, I bake it as instructed.

Is this dish gluten-free?

As written, it isn’t due to the breadcrumbs. But I’ve made it gluten-free easily by using gluten-free breadcrumbs or omitting them altogether.

Conclusion

Seafood Gratin with Mushrooms is one of those dishes I return to again and again. It’s rich, savory, and deeply satisfying, yet easy enough to whip up any night of the week. Whether I’m feeding guests or just indulging in something cozy and comforting, this gratin always hits the mark.

Recipe:

Seafood Gratin with Mushrooms

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

No reviews

Author: Cheryl
Total Time: 40 minutes
Yield: 4 servings

Print Recipe

Description

This Seafood Gratin with Mushrooms is a creamy, oven-baked comfort dish that combines shrimp, scallops, and white fish with earthy mushrooms, all topped with golden bubbling cheese. It’s rich, elegant, and surprisingly simple—perfect for a cozy dinner or impressing guests.

Instructions

Preheat oven to 375°F (190°C).
Heat olive oil in a skillet over medium heat. Sauté onion and garlic for 2-3 minutes until softened.
Add mushrooms and cook for 3-4 minutes until tender.
Stir in seafood and cook for 2-3 minutes until just opaque.
Pour in heavy cream, stir, and simmer until slightly thickened. Season with salt and pepper.
Transfer mixture to a greased baking dish.
Mix Parmesan, mozzarella, and breadcrumbs in a small bowl. Sprinkle over seafood mixture.
Dot with butter and bake for 20-25 minutes, until golden and bubbling.
Garnish with chopped parsley. Serve hot.