Creamy smoked haddock and prawn pie

Method

1. Cook the potatoes in a pan of boiling salted water for 12 minutes until tender, then drain well. Add the crème fraîche, 1 tbsp mustard, 50ml of the milk and 55g of the butter. Season well and mash until smooth.
2. Meanwhile, to make the sauce, melt half the remaining butter in a medium saucepan over a medium- low heat. Add the flour, stir until it forms a smooth paste, then cook, stirring constantly, for 2 minutes. Off the heat, add a little of the milk and beat until smooth, then, over a low heat, gradually add the remaining milk, stirring, until smooth. Add the bay leaves and simmer for 5 minutes, then remove from the heat, season well and stir in 1 tsp mustard and the dill. (don’t worry if the sauce is thick, the seafood will add juice to the sauce while cooking to give it the perfect consistency.) Cool slightly.
3. Preheat the oven to 200°c/ fan180°c/gas 6. Place the fish and prawns in a 1.5-litre ovenproof dish, pour over the sauce and mix well. Add the eggs (if using), spoon over the mashed potato, scatter with the grated cheese and dot the surface with the rest of the butter.
4. Bake the pie for 30-35 minutes or until it is bubbling underneath and golden brown on top. Divide among plates and serve with buttered peas.