Ingredients:

  • 1 lb (450g) skinless, boneless white fish fillets (cod, haddock, or halibut), cut into 1-inch pieces
  • 1 lb (450g) large shrimp, peeled and deveined
  • 1/2 lb (225g) sea scallops, patted dry
  • 1 tbsp olive oil
  • 1/2 tsp salt
  • 1/4 tsp black pepper
  • 4 tbsp (57g) unsalted butter
  • 1 medium yellow onion, finely chopped
  • 2 cloves garlic, minced
  • 1/4 cup (30g) all-purpose flour
  • 3 cups (710ml) whole milk
  • 1/2 cup (120ml) dry white wine (such as Sauvignon Blanc or Pinot Grigio)
  • 1 tsp Dijon mustard
  • 1/4 cup (packed) fresh parsley, chopped
  • 1/4 cup (packed) fresh dill, chopped
  • 1/4 tsp grated nutmeg
  • Salt and freshly ground black pepper to taste
  • 1 cup (100g) panko breadcrumbs
  • 4 tbsp (57g) unsalted butter, melted
  • 1/4 cup (30g) grated Parmesan cheese
  • 1 tbsp fresh parsley, chopped
  • 1/2 tsp garlic powder
  • Pinch of salt

Instructions:

  1. Toss seafood with olive oil, salt, and pepper. Set aside.
  2. Melt butter in a large skillet. Sauté onion until softened. Add garlic and cook until fragrant.
  3. Whisk in flour and cook for 1 minute. Gradually whisk in milk until smooth.
  4. Stir in white wine, Dijon mustard, parsley, dill, and nutmeg. Season with salt and pepper to taste. Simmer until thickened.
  5. Gently stir in the seafood to the sauce and simmer until just cooked through and opaque (Don't overcook!).
  6. Pour the seafood mixture into the prepared baking dish.
  7. Combine panko breadcrumbs, melted butter, Parmesan cheese, parsley, garlic powder, and salt in a bowl. Mix well until evenly moistened.
  8. Sprinkle the breadcrumb mixture evenly over the seafood filling. Bake in a preheated oven at 375°F (190°C) until golden brown and bubbly, about 35-40 minutes.
  9. Let the casserole rest for 10 minutes before serving.