Succulent seafood bathed in a creamy sherry sauce with shallots, garlic and mushrooms, topped with crispy potato sticks and parmesan. It's the perfect New England Seafood Casserole Recipe for dinner parties, Sunday family dinner, or the holidays.

This casserole is creamy and savory, with extra flavor and crunch from a delicious potato stick topping. Depending on the seafood you include, it can also be as decadent or budget friendly as you like!
With a simple combination of white fish and shrimp, you can make a luxurious recipe at a good price. And if you're celebrating a special occasion, head to the fish market and spring for a more upscale combination including lobster tails or lump crab and the same perfect sherry cream sauce will have everyone begging for your recipe.
Ingredients for this casserole recipe:
Before we get to the step by step directions, a few notes about the ingredients:
Seafood: every seafood casserole deserves a healthy portion of white fish. I used hake, but cod, haddock, snapper and even tilapia are all great options. Along with the white fish, I like to add a shellfish like shrimp, sea scallops, bay scallops or lobster meat. Even crab meat could be a light and flavorful addition.
Sherry: the recipe calls for a small amount of dry sherry. Substitute dry white wine, if needed. If you prefer cooking without alcohol, substitute broth or stock, along with a squeeze of fresh lemon juice.
Crunchy topping: the holy trinity of potato sticks, parmesan and paprika make up our crazy delicious crispy topping. If you don't have any crispy potato sticks on hand, you can use crushed up potato chips, Ritz crackers or oyster crackers. Homemade bread crumbs would add a little crunch to the topping, or even panko crumbs.
Full ingredient list and measurements included in the printable recipe card below.
Step by Step Instructions:
1. Cook vegetables
To begin, preheat oven to 375°. Use one tablespoon of butter to generously grease four oven-safe individual casserole dishes. Arrange on a baking sheet and set aside.
Next, melt butter (remaining 3 tablespoons) in a large skillet over medium heat. Add mushrooms and shallot to the melted butter. Cook until soft, about 6 minutes.
2. Add spices and liquids
Add garlic and sherry (or white wine) and cook until liquid is reduced, about 1 minute. Add flour, salt and pepper, and cook, stirring until smooth, for 2 minutes.
Then whisk in stock and half and half. Bring to a simmer and cook until slightly thickened, 2-3 minutes.
3. Fold in seafood
Stir in fish and shrimp, lemon zest and chives. Stir to combine thoroughly, then remove from heat.
4. Add crunchy topping
Next mix potato sticks, Parmesan cheese, and paprika in a bowl.
Divide the creamy seafood mixture evenly among each baking dish, ensuring a balanced mix of seafood and sauce in each dish. Sprinkle crunchy top mixture evenly over each casserole dish. Transfer sheet pan with casseroles into oven gently.
5. Bake and serve
Bake in preheated oven until lightly browned and bubbling, about 20 minutes. Top your delicious casserole with diced chives and serve with a lemon wedge.
Looking for more delicious seafood casserole recipes?
- Stuffed Shrimp Casserole Recipe
- Lobster Casserole Recipe (Best Lazy Lobster!)
- Fabulous Fish Pie (Ling Recipe)
- Scallop Casserole Recipe
FAQ's and Serving Suggestions:
Most flaky white fish will work in this recipe, including cod, hake, turbot, haddock, snapper and even tilapia. Ling cod is a lovely firm white fish, if you can find it in your local grocery or fish market.
A simple Mediterranean Tossed Salad or Gazpacho Salad or light and flavorful options. Garlic Almond Green Beans or Sweet Carrots would be two more great options. And I love to serve this with a baguette. That creamy sherry sauce deserves a warm and crusty bread so we don't waste a single drop.
A dry white wine is a good option in place of sherry. If you're looking for a non-alcoholic option, try a splash of apple cider vinegar or fresh lemon juice. For non-pescatarians, chicken stock can be another good substitute for wine, but I recommend pairing it with a touch of acid (vinegar or citrus) to create balance.
To store leftover casserole, move to an airtight container and keep in the refrigerator for up to 3 days. To reheat, place fish casserole into a small saucepan and heat gently over medium-low heat until just warmed through. Alternately, you can warm in the oven at 350℉ and broil the last few minutes to re-crisp the potato sticks.
Baked Seafood Casserole (Best Crunchy Topping!)
- Total Time: 50 minutes
- Yield: 4 1x
Ingredients
For the casserole:
4 tablespoons butter, divided
¼ cup all purpose flour
2 shallots, diced
8 ounces cremini mushrooms
4 cloves garlic, grated
2 tablespoons dry sherry
1 cup seafood stock
1 cup half and half
1 pound of white fish, cut into 1 inch squares
12 ounces shrimp, scallops or lobster
¼ cup fresh chives, diced, plus more for garnish
1 tablespoon lemon zest, plus wedges for serving
1 teaspoon kosher salt
½ teaspoon black pepper
For the topping:
1 cup potato sticks
¼ cup shredded parmesan
¾ teaspoon paprika
Instructions
- Heat oven to 375°. Use one tablespoon of butter to generously grease four oven-safe individual casserole dishes. Arrange on a baking sheet and set aside.
- Next, melt remaining 3 tablespoons of butter in a large skillet over medium heat. Add mushrooms and shallot. Cook, stirring occasionally, until soft, about 6 minutes. Add garlic and sherry (or white wine) and cook until liquid is reduced, about 1 minute. Add flour, salt and pepper, and cook, stirring until smooth, for 2 minutes. Whisk in stock and half and half. Bring to a simmer and cook until slightly thickened, 2-3 minutes. Stir in seafood, lemon zest and chives.
- Divide the creamy seafood mixture evenly among the baking dishes, ensuring a balanced mix of seafood and sauce in each dish.
- Finally, mix crushed potato sticks, Parmesan cheese, and paprika in a bowl. Sprinkle crunchy mixture evenly over each casserole dish. Transfer sheet pan with casseroles into oven gently. Bake until lightly browned and bubbling, about 20 minutes.
- Top your delicious seafood casserole with diced chives and serve with lemon wedges.
Notes
Most flaky white fish will work in this recipe, including cod, hake, turbot, haddock, snapper, ling cod and even tilapia.
- Prep Time: 10
- Cook Time: 40
- Category: Easy Recipes
- Method: Oven and Stove Top
- Cuisine: American
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