Method

Stud a couple of the onion slices with the cloves. Put the onion slices in a large pan with the bay leaf, 450ml of the milk, the cream, cod and smoked cod. Bring just to the boil and simmer for 8 minutes. Lift the fish out on to a plate and strain the cooking liquor into a jug. When the fish is cool enough to handle, break it into large flakes, discarding the skin and bones. Sprinkle it over the base of a shallow 1.75 litre (3 pint) ovenproof dish.

Hard-boil the eggs for just 8 minutes, then drain and leave to cool. Peel and cut them into chunky slices and arrange on top of the fish.

Melt 50 g of the butter in a pan, add the flour and cook for 1 minute. Take the pan off the heat and gradually stir in the reserved cooking liquor. Return it to the heat and bring slowly to the boil, stirring all the time. Leave it to simmer gently for 10 minutes to cook out the flour. Remove from the heat once more, stir in the parsley and season with nutmeg, salt and white pepper. Pour the sauce over the fish and leave to cool. Chill in the fridge for 1 hour.

Boil the potatoes for 15-20 minutes. Drain, mash and add the rest of the butter and the egg yolk. Season with salt and freshly ground white pepper. Beat in enough of the remaining milk to form a soft, spreadable mash.

Preheat the oven to 200C/gas 6. Spoon the potato over the filling and mark the surface with a fork. Bake for 35-40 minutes, until piping hot and golden brown.