Preheat the oven to 220°C (425°F), Gas Mark 7.

Place the fish and bay leaf in a saucepan and add just enough water to cover. Cover the pan and simmer for 10 minutes or until the fish is cooked. Drain, reserving the cooking liquid and discarding the bay leaf. Cool and flake the fish.

Melt the butter in a saucepan, add the onion and cook for 5-10 minutes until softened. Stir in the flour. Add the Milk, and 4 tablespoons of the reserved cooking liquid. Bring to the boil, stirring continuously until thickened. Stir in the chopped eggs, parsley, fish and seasoning.

Roll out the pastry until it is 5 mm (1/4 inch) thick. Cut into six 15 cm (6 inch) squares. Divide the filling between the pastry squares. Brush the edges with beaten egg. Fold the pastry edges into the centre and pinch together to form a parcel. Place on a baking sheet and brush with the remaining beaten egg.

Bake for 15 - 20 minutes, then reduce the oven temperature to 180°C (350°F), Gas Mark 4 and cook for a further 10 minutes. Serve hot.