Creamy salmon and potato casserole
4 x 130g salmon fillets 700g potatoes, peeled and sliced thinly lengthways 1 tbsp olive oil 1 tbsp butter 1 garlic clove, peeled and crushed 1 onion, peeled and chopped 4 large leeks, trimmed and sliced 1 tbsp cornflour 250ml milk 100ml single cream 100g spinach 2 tbsp chopped flat-leaf parsley 100g Caerphilly cheese sea salt and black pepper Place the sliced potatoes in a large pan and cover with cold water. Bring to the boil, then simmer for 5 mins. In the meantime, steam the salmon in a steamer over the potatoes. Drain and refresh the potatoes in cold running water until cool. Allow the salmon to cool slightly before removing the skin and flaking the fish into large chunks. In a large saucepan, heat the oil and butter and sauté the garlic and onion for 10 mins. Add the leeks and cook on a medium heat, stirring occasionally, for 5 mins. Stir in the cornflour and cook for 1 min. Stir in the milk gradually and bring to the boil. Stir in the cream and spinach, and season with salt and pepper. Preheat the oven to 190°C/gas mark 5. In a large oven dish, place a layer of the potato slices, overlapping them, then pour over a quarter of the creamy sauce and top with the flaked fish and a sprinkling of parsley. Repeat a further three times, then grate over the cheese. Season with pepper and bake for 20 mins. Serve immediately.