- 5 medium potatoes, cut into even-sized chunks
1 oz butter
3-4 tablespoons milk
2 x 6 oz cod fillets, skinned, boned and cut into large chunks
2 x 6 oz salmon fillets, skinned, boned and cut into large chunks
3 oz baby spinach
For the cheese sauce
1 oz unsalted butter
1/4 cup plain flour
1 2/3 cup milk
3/4 cup Cheddar cheese, grated
Pinch of grated nutmeg Sea salt and freshly ground black pepper (optional)
Preheat the oven to 350°F.
Cook the potatoes in a pan of boiling water for about 15 minutes or until tender, then drain and mash with the butter and milk.
Meanwhile, make the cheese sauce, melt the butter in a medium pan over a medium heat and whisk in the flour until smooth. Slowly whisk in the milk, stirring constantly, so it doesn't become lumpy. When all the milk has been added, bring to the boil then turn the heat down and simmer, continuing to stir until the sauce is thick enough to coat the spoon or whisk. Stir in most of the cheese (reserving a little for the topping) and stir for a further 2 minutes until the cheese has melted and the sauce is thick and smooth. Add the nutmeg and season to taste.
Gently stir the fish and baby spinach into the cheese sauce and transfer it to a baking dish. Spoon the mashed potato on top and sprinkle reserved cheese. Place on a baking tray and bake for 35 minutes or until the cheese is bubbling and golden brown.