Halve the potatoes if they are large, and place in a pan of boiling water. Simmer for 15 minutes until just tender. Remove from the heat, drain, and leave to cool slightly
450 g potatoes
Meanwhile place a large frying pan on a medium heat. Add the olive oil and fry the leek for 10 minutes until softened and slightly coloured
1 tablespoon olive oil, 1 large leek
Sir the cornflour into the cold milk. Add to the pan along with the seasoning and nutmeg. Bring to a boil stirring constantly. Simmer for a couple of minutes until thickened.
400 ml milk, 2 tablespoon cornflour, salt and pepper, ⅛ teaspoon grated of nutmeg
Add the fish. Bring back up to a simmer and cook for 6-7 minutes, stirring occasionally, until the fish is just cooked through. (It will turn opaque when it is cooked.)
150 g salmon fillet, 150 g white fish fillets such as cod, pollack or basa, 150 g smoked haddock fillet
Grate the potato on a coarse grater, removing the skin as you go. Preheat the grill
Spoon the fish pie mix into an oven proof baking dish. Top with the grated potato and grated cheese. Grill until brown and bubbling - approximately 5-8 minutes
40 g grated cheddar or red leicester