Try this Suffolk Fish Pie recipe
Milk does the heaviest lifting in this preparation, acting simultaneously as the poaching liquid for the cod fillets and the foundation for the béchamel sauce that binds the seafood together. By gently simmering the fish directly in the dairy just until the flesh flakes apart easily at 145 degrees Fahrenheit, the liquid absorbs soluble proteins and sea-salt notes that enrich the final roux-thickened sauce without needing added stock. Standardizing this dual-purpose technique requires straining the poaching liquid carefully before whisking it into the melted butter and flour mixture to prevent curdling.
Building the dish relies on precise thermal staging to prevent the mashed potato topping from sinking into the sauce. Ensure the béchamel thickens fully over medium heat until it coats the back of a spoon before incorporating the chopped parsley and capers. Layer the flaked fish and sliced hard-boiled eggs into a buttered two-and-a-half-pint ceramic dish while the sauce remains warm, then spread the cold, cooked potatoes across the top. Roughening the surface with fork tines creates high points that catch direct heat from the 375-degree oven, yielding a deeply golden crust after thirty minutes.