Light haddock pie with pesto mash

Place all the haddock in a single layer in a roasting tin or a large frying pan, add the bay leaf, milk and pepper to taste and poach over a medium heat for 6-8 minutes until the flesh turns opaque and flakes easily when tested with a knife.

Meanwhile, peel the potatoes and cut them into chunks.

Put a large saucepan of lightly salted water on to boil. Remove the fish from the tin, and skin and flake the flesh, checking for any bones. Strain the milk into a measuring jug, discard the bay leaf and set the milk aside.

Add the potatoes to the saucepan, bring the water back to the boil and cook the potatoes for 10-15 minutes until they are tender.

Drain the potatoes well, reserving a little of the water, and return them to the pan over a medium heat to dry. Mash well, then beat in 1 tablespoon of the spread, check the seasoning and stir in the pesto to taste. (If the potatoes are a little dry, beat in 1-2 tablespoons of the reserved cooking water.) Set the mash aside. Heat the grill to high.

Melt the remaining spread in a saucepan, add the leeks or onion and cook for 7 minutes, or until softened. Pour in the cider, increase the heat to high and boil until the cider is reduced by half.

Stir in the flour and continue boiling for about 1 minute, then gradually stir in the reserved poaching milk, stirring briskly until the sauce thickens and becomes smooth. Reduce the heat, season to taste and simmer for 3 minutes, stirring occasionally.

Stir in the prawns, crème fraîche and flaked fish and reheat for 2 minutes. Be careful not to let the mixture boil or to break up the fish.

Spoon the fish mixture into a shallow 20 × 30 cm (8 × 12 in) flameproof serving dish. Spread the pesto mash over the top and smooth the surface. Sprinkle on the breadcrumbs and arrange the tomato slices on top.

. Reduce the grill heat to medium and grill the pie until it is crisp, but not burnt, then serve.