|1. Preheat the oven to 190°C/375°F/Gas Mark 5.
2. Lay the fish in a large frying pan and pour over the milk. Cover and bring slowly to the boil. Simmer gently for 5-7 minutes or until the fish flakes apart. Remove the fish and place into one large ovenproof dish or four individual dishes.
3. Add the soup to the milk and heat gently until thoroughly combined.
4. Add the sweet corn, peas, parsley, nutmeg (if using), the lemon juice and pepper, and pour over the fish.
5. Place the potatoes on top of the fish and scatter with cheese.
6. Bake for 25 minutes or until the potatoes are beginning to turn golden and the fish filling is hot and bubbling.