Rich fish pie

Method

1. Preheat the oven to 190°C (375°F, gas mark 5). Place all the fillets in a large frying pan and season. Pour over the milk, add the bay leaves and simmer. Cover and cook gently for 5 mins until cooked through. Set aside until cool.
2. When cool, remove the fish and sieve the milk, reserving the strained liquid. Remove the fish skin, flake and remove any bones.
3. Heat the butter in a large pan, add the fennel and cook over a low heat until softened and lightly coloured. Add the flour and cook, stirring all the time, for 2 mins. Remove from the heat and beat in the wine and vermouth until smooth.
4. Add the reserved cooking liquid and return to the pan. Slowly bring to the boil, whisking all the time. Simmer gently for 10 mins until thickened. Whisk in the mustard and cream and season. Fold in the fish, prawns and chives. Spoon into the baking dish and set to one side.
5. To make the topping, place the potatoes and sweet potatoes in a large pan, cover with water and bring to the boil. Simmer for 15 mins until just tender. Drain and set aside until cool.
6. Peel off the skins, grate into a large bowl, season and combine. Spoon over the fish to cover, dot with the butter and bake for 40 mins until piping hot and golden. Serve with steamed greens.