Put the milk and onion on to the boil.

Add the haddock to the milk and poach for 5-8 minutes, until the flesh is flaky.

Place 1oz of butter in to another saucepan over a medium heat. Let the butter simmer, add the onions and cook until soft, but not brown.

Add the leeks and mushrooms to the onion and cook for 8 minutes. In another pan, melt 2oz butter, then fold in the flour, stir to combine. Add one glass of white wine to the onion and mushroom mix. Using a sieve, ladle poaching milk from the saucepan with the fish into the sauce, stirring thoroughly as it is applied.

Using a strainer, pour the wine from the onions and mushroom mix into the sauce. Add the cream. Mix thoroughly, season to taste.

Combine the leeks, mushrooms, prawns, scallops, haddock, parsley and dill.

Add enough of the sauce to coat. Mix together. Put all of the mix into the baking dish.

Roll out the pastry. Trim strips of the pastry and attach to the edge of the dish. Using water as an adhesive. Trim the remaining pastry to fit over the top of the dish and attach to the pastry strip. Paint the pastry with egg wash.

Place in a preheated oven 200 °C/gas 4 for 30 minutes, or until hot and golden brown.