Keto Crab Imperial with Old Bay Crispy Gratin

There’s something about seafood dishes that instantly makes dinner feel a little more special, and this Keto Crab Imperial with Old Bay Crispy Gratin is no exception. It’s rich, creamy, and packed with sweet crab meat, all topped with a golden, cheesy crust seasoned with the unmistakable flavor of Old Bay. Even better, it’s naturally low in carbs, making it a wonderful option for anyone following a keto lifestyle without sacrificing comfort or flavor.

I first learned about Crab Imperial from a family friend who grew up near the Chesapeake Bay. She always said it was the dish her family served for birthdays, holidays, and Sunday dinners because it was elegant without being difficult to prepare. After giving it a keto-friendly twist, it quickly became one of my favorite seafood recipes.

Last weekend, I made it for my family as a special Saturday dinner. As the creamy crab filling baked in the oven, the aroma of butter, garlic, Old Bay seasoning, and bubbling cheese filled the kitchen. Everyone kept asking when it would be ready because it smelled so incredible.

When I pulled the gratin from the oven, the top was beautifully golden and crisp while the inside stayed creamy and loaded with tender crab. My husband loved the crunchy topping, my parents appreciated the delicate crab flavor, and even my kids—who don’t always choose seafood—asked for another serving. We paired it with roasted asparagus and a fresh green salad, and there wasn’t a single bite left.

Now, this Keto Crab Imperial is one of my favorite recipes whenever I’m celebrating something special, craving a comforting seafood dinner, or simply enjoying a relaxing weekend cooking with my family. It’s elegant enough for guests but easy enough for a weeknight meal.

If you’re looking for a restaurant-quality keto seafood recipe that’s rich, creamy, and full of classic coastal flavor, this one is sure to impress.

Why You’ll Love This Recipe

Low-carb and keto-friendly
Ready in about 40 minutes
Rich, creamy, and flavorful
High in protein
Perfect for holidays or dinner parties
Naturally gluten-free
Easy to prepare

What Is Crab Imperial?

Crab Imperial is a classic American seafood casserole traditionally made with lump crab meat, a creamy mayonnaise-based sauce, seasonings, and baked until hot and golden. This keto version skips breadcrumbs and uses a cheesy gratin topping for extra flavor and texture.

Ingredients

For the Crab Imperial

1 pound lump crab meat, picked over for shells
½ cup mayonnaise
2 tablespoons sour cream
1 large egg
1 teaspoon Dijon mustard
1 teaspoon Old Bay seasoning
1 teaspoon fresh lemon juice
1 teaspoon Worcestershire sauce
1 garlic clove, minced
2 tablespoons grated Parmesan cheese
1 tablespoon chopped fresh parsley
Salt and black pepper, to taste

For the Crispy Gratin Topping

1 cup shredded mozzarella cheese
¼ cup grated Parmesan cheese
1 teaspoon Old Bay seasoning
1 tablespoon melted butter

Optional Garnishes

Fresh parsley
Lemon wedges
Extra sprinkle of Old Bay seasoning

Ingredient Notes

Lump Crab Meat

Lump crab meat provides the best texture and sweet, delicate flavor. Handle it gently to keep the pieces intact.

Old Bay Seasoning

Old Bay gives the dish its signature coastal flavor. Adjust the amount to your taste if you prefer a milder seasoning.

Parmesan Cheese

Adds a savory, nutty flavor and helps create a beautifully browned topping.

Lemon Juice

Fresh lemon juice brightens the rich filling and complements the crab perfectly.

Kitchen Equipment Needed

Mixing bowl
8-inch baking dish or gratin dish
Rubber spatula
Small bowl
Oven

Step-by-Step Instructions

Step 1: Preheat the Oven

Preheat your oven to 375°F (190°C).

Lightly grease a baking or gratin dish.

Step 2: Make the Crab Filling

In a large bowl, whisk together:

Mayonnaise
Sour cream
Egg
Dijon mustard
Old Bay seasoning
Lemon juice
Worcestershire sauce
Garlic
Parmesan cheese
Parsley

Gently fold in the lump crab meat, taking care not to break up the large pieces.

Step 3: Fill the Dish

Spread the crab mixture evenly into the prepared baking dish.

Step 4: Prepare the Topping

In a small bowl, combine:

Mozzarella cheese
Parmesan cheese
Old Bay seasoning

Sprinkle the mixture evenly over the crab filling.

Drizzle with melted butter.

Step 5: Bake

Bake for 20–25 minutes, or until the filling is hot and the cheese is melted.

For a crispier golden topping, broil for 2–3 minutes, watching carefully to prevent burning.

Step 6: Garnish and Serve

Let the dish rest for 5 minutes before serving.

Garnish with fresh parsley and serve with lemon wedges.

Expert Tips

Use Fresh Crab if Possible

Fresh lump crab meat gives the best flavor and texture, though refrigerated pasteurized crab also works well.

Fold Gently

Mix carefully to keep the crab pieces large and tender.

Don’t Overbake

Overcooking can make the crab less tender and dry.

Broil Carefully

The topping browns quickly under the broiler, so keep a close eye on it.

Delicious Variations

Crab and Shrimp Imperial

Add chopped cooked shrimp for an even heartier seafood casserole.

Spicy Version

Mix a pinch of cayenne pepper into the filling for a little heat.

Extra Cheesy

Blend shredded Gruyère or white cheddar into the topping for additional richness.

Herb Lover’s Version

Add fresh dill or chives to the filling for extra freshness.

What to Serve with Keto Crab Imperial

This dish pairs beautifully with:

Roasted asparagus
Garlic butter green beans
Steamed broccoli
Cauliflower mash
Zucchini noodles
Mixed green salad

Storage Instructions

Refrigerator

Store leftovers in an airtight container for up to 3 days.

Freezer

Freezing is not recommended, as the creamy filling may separate and the crab texture can become grainy after thawing.

Reheating

Reheat gently in a 325°F (163°C) oven until warmed through, or microwave individual portions on medium power.

Nutritional Benefits

Each serving provides:

High-quality protein from crab
Healthy fats from mayonnaise and cheese
Calcium from Parmesan and mozzarella
Lower carbohydrates than traditional Crab Imperial made with breadcrumbs

Nutrition values will vary depending on the ingredients used.

Frequently Asked Questions

Is this recipe keto-friendly?

Yes. It replaces the traditional breadcrumb topping with a low-carb cheese gratin.

Can I use canned crab meat?

Yes, although fresh or refrigerated lump crab meat provides the best flavor and texture. Drain canned crab well before using.

Can I prepare it ahead of time?

Absolutely. Assemble the dish, cover it, and refrigerate for up to 24 hours before baking.

What if I don’t have Old Bay seasoning?

You can make a similar blend using paprika, celery salt, black pepper, mustard powder, and a pinch of cayenne, though the flavor won’t be exactly the same.

Can I use imitation crab?

Imitation crab is generally higher in carbohydrates because it contains starches and sugars, so it’s not the best choice for a keto diet.

How do I keep the crab pieces intact?

Fold the crab gently into the sauce instead of stirring vigorously.

Is this recipe gluten-free?

Yes, as long as your Worcestershire sauce and seasonings are certified gluten-free.

Can I add vegetables?

Yes. Chopped spinach, sautéed mushrooms, or diced bell peppers can be added, but they’ll change the traditional character of the dish.

Can I make individual portions?

Definitely! Divide the mixture among small ramekins and reduce the baking time to about 15–18 minutes.

Can I use this as a stuffing?

Yes. It pairs wonderfully with baked fish, chicken breasts, or large mushroom caps.

Final Thoughts

This Keto Crab Imperial with Old Bay Crispy Gratin is one of those dishes that feels both elegant and comforting. After making it for my family last weekend and watching everyone scrape their plates clean, I knew it would become one of our favorite seafood dinners.

With sweet, tender crab, a creamy seasoned filling, and a crispy golden cheese topping, every bite delivers rich flavor and satisfying texture. Whether you’re preparing a special holiday meal, entertaining guests, or simply treating yourself to a restaurant-quality dinner at home, this keto-friendly recipe is sure to become a standout favorite.

Serve it with your favorite low-carb sides, a squeeze of fresh lemon, and enjoy every creamy, cheesy bite.