New England Fish Pie

Instructions

1. Prepare the potatoes
   Place the potatoes in a large pot of salted water. Bring to a boil and cook until fork-tender, about 15-20 minutes. Drain well, then return to the pot. Add 2 tablespoons of butter and the warmed milk. Mash until smooth and season with salt and pepper. Set aside.
2. Prepare the seafood filling base
   Preheat oven to 375°F (190°C). In a large skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the onion and celery, cooking until softened but not browned, about 5-7 minutes.
3. Create the sauce
   Sprinkle the flour over the vegetables and stir constantly for 2 minutes to cook out the raw flour taste. Gradually whisk in the seafood stock, stirring continuously to prevent lumps. Bring to a simmer and cook until thickened, about 3-4 minutes. Stir in the heavy cream and simmer for another 2 minutes.
4. Add the seafood
   Gently fold in the cod, shrimp, and scallops. Cook for just 2 minutes - the seafood will finish cooking in the oven. Add the frozen peas, dill, and parsley. Season with salt and pepper to taste. Remove from heat.
5. Assemble the pie
   Transfer the seafood mixture to a 9x13 inch baking dish, spreading it evenly. Carefully spread the mashed potatoes over the top, creating peaks and valleys with a fork for a textured finish that will brown nicely.
6. Bake to perfection
   Bake in the preheated oven for 25-30 minutes, until the potato topping is golden brown and the filling is bubbling around the edges. If needed, place under the broiler for 2-3 minutes to achieve a more golden crust.
7. Rest and serve
   Allow the fish pie to rest for 10 minutes before serving. This helps the filling set and prevents it from being too runny when served. Garnish with additional fresh herbs if desired.