Keto Seafood Au Gratin Recipe with Video Tutorial

This keto seafood au gratin is full of flavor and ready in under 30 minutes. It works beautifully as an appetizer or a main course. In addition to being keto-friendly, this recipe can easily be adapted for paleo or Whole30 preferences.

Ingredients for Keto Seafood Au Gratin

• Seafood (shrimp, lump crab, lobster, or chopped salmon)
• Creole or Old Bay seasoning
• Whipping cream (or half & half as desired)
• The Holy Trinity: onion, bell pepper, celery
• Grated Parmesan cheese
• Lemon juice
• Butter or ghee
• Almond flour (for the keto crust)

How To Make Keto Seafood Au Gratin

This recipe uses both the stovetop and the oven and comes together quickly—usually in 30 minutes or less.

1. Preheat the oven to 450°F (230°C).
2. In a medium saucepan, heat the butter or ghee. Add diced onion, diced celery, and diced bell pepper. Sauté 3–5 minutes until the vegetables soften.
3. Pour in the whipping cream and bring the mixture to a gentle boil.
4. Lower the heat to medium and stir in Creole or Old Bay seasoning, lemon juice, and 1/2 cup grated Parmesan. Cook for another minute.
5. Add the seafood (shrimp or your choice) and cook over medium heat until the seafood is opaque and cooked through, about 4–6 minutes for shrimp. Turn off the heat and let the mixture cool slightly so it thickens.
6. Divide the mixture into 2 or 4 ovenproof dishes depending on whether you want main-course or appetizer portions.
7. For the keto crust, combine 1 teaspoon seasoning, 2 tablespoons grated Parmesan, and 2 tablespoons almond flour. Sprinkle this mixture evenly over each dish and lightly spray the tops with cooking spray if desired.
8. Bake for about 10 minutes or until the edges bubble and the top begins to brown.
9. Garnish with chopped fresh parsley and serve warm.

FAQs

What Is Au Gratin?

Au gratin is a French technique where a dish is topped with breadcrumbs and cheese (or a substitute) and baked until a golden crust forms. This recipe replaces breadcrumbs with a keto-friendly crust made from almond flour, grated Parmesan, and a no-salt or low-sodium seasoning.

What Type Of Seafood To Use

Use your favorite seafood, keeping in mind how it holds up to cooking. Shrimp, lump crab meat, lobster, and firm fish like salmon all work well. Make sure shellfish are cleaned and chopped into bite-sized pieces for even cooking and easy serving.

What Type Of Seasoning To Use

Old Bay or Creole/Cajun seasoning are excellent choices for this dish. Use a store-bought blend or your own homemade seasoning. For lower sodium, choose a no-salt seasoning blend and adjust to taste.

The Holy Trinity

The “holy trinity” in Creole cooking replaces the classic French mirepoix and consists of equal parts diced onion, bell pepper, and celery. It creates a flavorful base for many Creole dishes—gumbo, jambalaya, and étouffée—and provides a savory foundation for this seafood au gratin. It pairs especially well with Creole or lite Creole seasoning.

The Cream Sauce

The sauce is flexible: use heavy whipping cream, light whipping cream, or half & half depending on your preference and dietary needs. Butter adds richness—1 to 2 tablespoons works well; two tablespoons give a richer finish. Taste and adjust seasoning as you go.

How To Serve Seafood Au Gratin

This dish is versatile. Serve it as an appetizer—yielding four smaller portions—or as a main course with two larger portions. It reheats well and makes a satisfying starter or a rich seafood entrée.

Tips For This Keto Au Gratin Recipe

• If the crust browns faster than the filling bubbles, lower the oven temperature slightly or cover the tops lightly with foil, or mist the crust with a little cooking spray to slow browning.
• The au gratin will continue to thicken as it cools, so allow it to rest a few minutes before serving.

Other keto recipes you may enjoy:

Air Fryer Keto Fried Mushrooms

Keto Buffalo Chicken Dip

Instant Pot Keto Brisket Chili

Baked Keto Italian Shrimp

I used a 2-quart saucepan.

This post was sponsored by Tony Chachere’s; all recipes and opinions are my own.