Crab and Shrimp Casserole

Prep Time: 25 minutes | Cook Time: 35 minutes | Total Time: 1 hour
Serving Size: 6-8 servings
Cooking Intensity: Moderate

Elegance and ease rarely coexist in the kitchen, but this Creamy Crab and Shrimp Casserole is the glorious exception. Imagine sweet, tender shrimp and delicate, luxurious lump crab meat enveloped in a rich, sherry-kissed cream sauce, topped with a golden, buttery crumb crust that crackles with every bite. This dish transforms humble ingredients into a show-stopping centerpiece, perfect for holiday gatherings, celebratory dinners, or when you simply want to treat your loved ones to something special. It captures the essence of a coastal feast but delivers it in the comforting, familiar form of a bake-and-serve casserole. It’s impressive without being intimidating, rich without being heavy, and destined to become a cherished recipe in your collection.

The Secret to Success: The key to this casserole’s luxurious texture and flavor is a gentle touch and quality ingredients. Handle the crab meat with care to preserve its delicate chunks, and use a good, dry sherry for a nutty depth that can’t be replicated. The creamy sauce, built from a simple roux, is the silky glue that brings the ocean’s bounty together in perfect harmony.

Ingredients

For the Seafood & Aromatics:

1 pound large raw shrimp (31-40 count), peeled, deveined, tails removed
1 pound jumbo lump crab meat, carefully picked over for shells
4 tablespoons (½ stick) unsalted butter, divided
1 medium leek, white and light green part only, halved and thinly sliced
½ cup finely diced celery
¼ cup finely diced red bell pepper
3 cloves garlic, minced
¼ cup dry sherry (or dry white wine)
2 tablespoons fresh lemon juice
2 tablespoons chopped fresh parsley, plus more for garnish
1 tablespoon chopped fresh tarragon (or 1 teaspoon dried)

For the Cream Sauce:

¼ cup all-purpose flour
2 cups whole milk, warmed
½ cup seafood or chicken broth
1 cup heavy cream
1 teaspoon Dijon mustard
½ teaspoon Old Bay seasoning
½ teaspoon smoked paprika
¼ teaspoon freshly grated nutmeg
Kosher salt and white pepper to taste (black pepper is fine)

For the Crumb Topping:

1 ½ cups panko breadcrumbs
¼ cup (½ stick) unsalted butter, melted
⅓ cup grated Parmesan cheese
2 tablespoons chopped fresh chives
½ teaspoon lemon zest

Instructions

1. Prepare the Seafood & Vegetables (A Gentle Start)

Preheat your oven to 375°F (190°C). Butter a 2.5 to 3-quart baking dish (like a 9×13 or an oval gratin dish).
Pat the shrimp and crab meat very dry with paper towels. Set the crab aside in a large mixing bowl.
In a large skillet, melt 2 tablespoons of butter over medium heat. Add the sliced leek, diced celery, and red bell pepper. Sauté for 6-8 minutes, until softened but not browned.
Add the minced garlic and cook for 1 more minute until fragrant.
Increase heat to medium-high. Push vegetables to the side and add the shrimp to the skillet in a single layer. Cook for 1-2 minutes per side, just until they turn pink and opaque. Do not overcook. Transfer the shrimp to the bowl with the crab meat.
To the skillet with the vegetables, add the dry sherry and lemon juice. Bring to a simmer, scraping up any browned bits, and cook for 1-2 minutes until slightly reduced. Remove from heat and pour this mixture over the seafood. Gently fold in the parsley and tarragon. Set aside.

2. Create the Luxurious Cream Sauce (The Heart of the Dish)

In the same skillet (no need to wash it), melt the remaining 2 tablespoons of butter over medium heat. Sprinkle in the flour and whisk constantly to form a paste (roux). Cook for 1-2 minutes to eliminate the raw flour taste.
Very slowly, begin whisking in the warmed milk, followed by the broth, ensuring the mixture is smooth with each addition. Whisk in the heavy cream.
Add the Dijon mustard, Old Bay, smoked paprika, and nutmeg. Bring the sauce to a gentle simmer, whisking frequently. Let it cook for 3-5 minutes until it thickens enough to coat the back of a spoon. It should be the consistency of a thick chowder. Season carefully with salt and white pepper. Remember, the seafood and Parmesan will add saltiness.
Remove the sauce from the heat.

3. Assemble with Care

Pour the warm cream sauce over the seafood and vegetable mixture. Using a large, flexible spatula, fold everything together gently and with minimal strokes to avoid breaking up the precious lumps of crab. The mixture will be loose.
Carefully pour the entire mixture into your prepared baking dish, spreading it evenly.

4. Add the Flavorful Crust & Bake

In a small bowl, combine the panko breadcrumbs, melted butter, Parmesan cheese, chives, and lemon zest. Mix until the crumbs are evenly moistened.
Sprinkle the crumb mixture evenly over the entire surface of the casserole.
Place the baking dish on a baking sheet (to catch any potential bubbles) and bake in the preheated oven for 25-30 minutes, until the casserole is bubbling enthusiastically around the edges and the topping is a deep, golden brown.

5. Rest and Serve

Crucial Step: Remove the casserole from the oven and let it rest on a wire rack for 10-15 minutes. This allows the sauce to set slightly, making serving easier and letting the flavors meld perfectly.
Garnish with additional fresh parsley or chives. Serve directly from the baking dish.

Chef’s Notes & Tips for Success

Seafood Selection: For the best flavor and texture, use wild-caught shrimp and the highest-quality lump crab you can find (fresh, pasteurized, or well-drained frozen). Avoid imitation crab.
The Sherry Factor: A good dry sherry (like Amontillado) adds irreplaceable depth. If you must substitute, use a dry white wine and add a tiny pinch of sugar.
Gentle Does It: The most common mistake is overmixing. Fold the crab and shrimp into the sauce just until combined to keep the crab meat in beautiful, identifiable pieces.
Make-Ahead Strategy: You can prepare the casserole fully (through adding the topping) up to 8 hours ahead. Cover and refrigerate. Let it sit at room temperature for 30 minutes while the oven preheats, then bake as directed, adding 5-10 minutes to the bake time.
Serving Suggestions: This rich casserole is a complete meal but pairs beautifully with a simple, crisp green salad with a lemon vinaigrette to cut the richness, or with steamed asparagus or haricots verts.
Storage & Reheating: Store leftovers covered in the refrigerator for up to 2 days. Reheat gently in a 300°F oven, covered with foil, until warmed through. Microwave reheating is not recommended as it can make the seafood rubbery and the sauce separate.

Nutritional Information (Per Serving, based on 8 servings)

Calories: ~480 kcal
Total Fat: 32g
Saturated Fat: 19g
Cholesterol: 225mg
Sodium: 680mg
Total Carbohydrates: 20g
Dietary Fiber: 1g
Sugars: 6g
Protein: 28g

Note: Nutritional information is an estimate calculated using a standard online nutrition calculator. Values will vary based on specific ingredients and brands used, particularly the butter, cream, and crab meat.