2 salmon fillets, about 150 g (5 oz) each, cut into chunks
200 g (7 oz) crème fraîche
8 fresh lasagne sheets
50 g (2 oz) dried breadcrumbs
salt and pepper
Pour half the hot stock over the leeks in a saucepan and boil for 5 minutes until soft. Pour the remaining stock over the salmon in a separate saucepan and simmer for 5 minutes until the fish flakes easily. Drain both, reserving the stock. Mix the stock with the crème fraîche. Flake the fish, discarding the skin and any bones.
Stir together the leeks and salmon with 6 tablespoons of the crème fraîche mixture to loosen, then season. Place some of the mixture along one long side of a lasagne sheet. Roll up and place, seam-side down, in a baking dish. Repeat with the remaining lasagne sheets. Pour over the remaining crème fraîche mixture and sprinkle with the breadcrumbs.
Place in a preheated oven, 200°C (400°F), Gas Mark 6, for 15–20 minutes until golden and cooked through.