Shrimp and Crab Au Gratin

Experience the luxurious flavors of the sea with Shrimp and Crab au Gratin, a dish that’s as indulgent as it is comforting. Tender crab meat and succulent shrimp are enveloped in a creamy sauce, topped with cheese, and baked to golden perfection. It’s served over rice for a meal that promises to be a memorable culinary delight. Perfect for special occasions or when you crave a taste of the ocean’s bounty.

Shrimp and crab au gratin over rice on a plate.

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What Makes Shrimp and Crab au Gratin Such a Comfort Food?

For many people, seafood is something that’s delicate and light, but the French don’t do subtle very well. That’s particularly noticeable in this Shrimp and Crab au Gratin recipe, a play on the classic Sole au Gratin.

This seafood au gratin recipe is loaded with tender morsels of seafood in a cheesy Mornay sauce. And as if that isn’t indulgent enough, a layer of shredded cheese is baked into golden brown on top. If you want something traditional that still appeals to modern taste, you can’t do better than this dish. 

Why You’ll Love This Recipe 

Don’t be intimidated by the foreign name; this dish is nothing more than a casserole. “Au gratin” means “to grate or scrape” in French, and it is pretty apparent why that’s the name of this dish once you know how to prepare it.

This recipe is loaded with ooey-gooey cheese! The creamy Mornay sauce makes this recipe perfect for those who may not typically like the taste of seafood, so it’s no surprise when even the pickiest eater will at least try it.

Besides being a crowd-pleaser, this recipe is substitution-friendly enough to fit your preferences. 

Crab and Shrimp au gratin Recipe Ingredients

For this seafood au gratin recipe, you’ll need:

  • Unsalted butter 
  • Celery
  • White onion 
  • All-purpose flour
  • Salt
  • Finely ground black pepper 
  • American cheese, cubed 
  • Whole milk
  • Crab Meat
  • Shrimp, cooked
  • Tabasco Sauce
  • Cheddar cheese, shredded
Shrimp and crab au gratin ingredients on a tray.

How to Make Baked Shrimp and Crab au Gratin 

To prepare the Mornay sauce:

  1. Put the unsalted butter in a saucepan over medium-low heat. 
  2. While the butter is melting, finely mince the celery and onion. Reserve both for later.
  3. When the butter stops foaming, add the minced celery and onion to the saucepan. Stir the veggies and sauté for about a minute until they soften. 
  4. Sprinkle the flour into the saucepan and stir well to coat the flour in butter. Cook for a couple of minutes until the flour darkens to a pale blond color and there is a strong aroma of freshly baked pie crust. 
  5. Whisk in the milk and Tabasco sauce. Continue to whisk until the sauce thickens slightly.
  6. Add the American cheese and stir with a spoon until it melts. 
  7. Remove the saucepan from the heat and stir in the crab meat and shrimp. 

To bake the seafood au gratin:

  1. Preheat the oven to 350°F.
  2. Lightly grease a gratin or a casserole dish and pour in the Mornay sauce with seafood. 
  3. Top the seafood mixture with the shredded cheddar cheese. 
  4. Bake for 20 minutes. If the top still isn’t golden brown, finish it under the broiler.

As an alternative, use ramekins for individual servings.

Collage of making shrimp and crab au gratin.

Crab and Shrimp au Gratin Recipe Variations

You can use the same general directions and replace the shrimp and crab meat with other ingredients.

Besides the classic sole au gratin, try scallops or lobster.

Add some chopped shallots to go along with the celery and onions.

Bump up the cheese flavor with sharp cheddar cheese.

Give it a little kick of heat with a dash of cayenne pepper or hot sauce.

Add a layer of bread crumbs on top of the shredded cheese for a crunchier crust.

If you are after a more authentic taste, try replacing the American and cheddar cheese with Gruyère. Swiss, Fontina, and Parmesan are also good options. 

Shrimp and crab au gratin over rice on a plate and a fork next to it.

What to Serve Seafood au Gratin With

Enjoy this Shrimp and Crab au Gratin recipe as a main course or an appetizer. When serving it as a starter, the best way to eat it is on toasted bread rounds. To turn the gratin into a main course, try adding one or more of these components to the meal:

  • White rice. Spoon a large portion of the casserole directly over a mound of white rice for a casual and filling dinner in a bowl. This is an excellent option for buffets or game-day dining. 
  • Steamed vegetables. Some veggies like carrots, broccoli, and cauliflower on the side go a long way to help lighten up this rather heavy casserole. Since the seafood au gratin is so flavorful, season the vegetable with only a bit of salt and pepper, and skip the butter.  
  • Roasted potatoes. For a tasty way to add bulk to your seafood casserole without a lot of hassle, make some roasted red potatoes.
  • Wine. A crisp and dry white wine pairs wonderfully with this seafood dish. Chardonnay, Pinot Grigio, or Sauvignon Blanc are great choices.

How to Store the Leftovers

Although you can save baked but unserved Shrimp and Crab au Gratin in the fridge, you need to be careful how you cool it. A casserole left on the counter can take a long time to return to room temperature. That means the food will be in the danger zone for too long.

To prevent anyone from getting sick, it is a good idea to quickly cool the seafood au gratin in an ice bath before covering the dish with aluminum foil and putting it in the fridge. 

Heating seafood au gratin multiple times can dry it out; therefore, if you plan to serve the casserole several hours later, don’t bake it. Instead, prepare the gratin to the point right before baking, cover it, and put it in the fridge. Allow the seafood casserole to come to room temperature before baking for 20 minutes in a 350°F oven. 

Do not freeze this dish, either before it is baked or after. 

How Long Does This Last?

Baked Shrimp and Crab au Gratin will stay good in the fridge for two to three days, although the texture of the seafood will become more mealy the longer it sits.

Shrimp and crab au gratin in a baking dish and over rice on a plate.

Favorite Shrimp and Crab Recipes

More Au Gratin Recipes

Find lots of easy casserole recipes and the best seafood recipes on CopyKat!

Many thanks go to Bill Spalding for this recipe.

Shrimp and crab au gratin over rice on a plate.

Shrimp and Crab Au Gratin

This shrimp and crab au gratin is perfect for a weeknight. 
5 from 1 vote
Print Pin Rate Add to Collection
Course: Main Course
Cuisine: Seafood
Keyword: Crab and Shrimp Au Gratin
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes
Servings: 6
Calories: 578kcal


  • 4 tablespoons butter
  • 1/2 cup finely diced celery
  • 1/2 cup finely diced white onion
  • 4 tablespoons all-purpose flour
  • 1/2 teaspoon salt
  • 1/2 teaspoon finely ground black pepper
  • 5 ounces American cheese cubed
  • 1/2 teaspoon salt
  • 2 cups milk
  • 1/2 teaspoon Tabasco sauce
  • 1/4 pound cooked crab meat
  • 1/2 pound cooked shrimp
  • 1 cup shredded cheddar cheese
  • 3 cups cooked rice to serve


  • Preheat the oven to 350°F.
  • Melt the butter in a medium-sized saucepan over medium-low heat. Add the celery and onion and cook, stirring occasionally, until the onions are translucent.
  • Add the flour, stir to incorporate, and cook for about 2 minutes or until fragrant. Add the milk and stir constantly until thickened. Add the cubed American cheese and stir until melted. Then add the crab and shrimp.
  • Pour the mixture into a greased 1 1/2–quart casserole dish and top with shredded cheese. Bake for 20 minutes and serve over hot cooked rice.


Calories: 578kcal | Carbohydrates: 82g | Protein: 27g | Fat: 13g | Saturated Fat: 7g | Cholesterol: 142mg | Sodium: 1005mg | Potassium: 316mg | Fiber: 1g | Sugar: 4g | Vitamin A: 430IU | Vitamin C: 3.1mg | Calcium: 439mg | Iron: 2.1mg

About Stephanie Manley

I recreate your favorite restaurant recipes, so you can prepare these dishes at home. I help you cook dinner, and serve up dishes you know your family will love. You can find most of the ingredients for all of the recipes in your local grocery store.

Stephanie is the author of's Dining Out in the Home, and's Dining Out in the Home 2.

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Reader Interactions


  1. Cjholliday3

    Very poor recipe if you must use any kind of “pasturized cheese spread” when preparing a high quality gourmet cheese sauce is infinitely preferable both in quality and flavor.
    C. Holliday

    • Stephanie Manley

      So you made the recipe and it was bad? Or you just don’t like the ingredients? Processed cheese has its places in life, they are limited, but sometimes they are perfect for *some* recipes

5 from 1 vote

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