Preheat oven to gas 5

Put fish in oven proof dish with milk

Add salt and pepper, bake for 15 minutes.

Strain milk from fish and reserve.

Flake the fish and put back in bowl, add prawns.

Melt butter in saucepan and add flour, mix well.

Remove from heat and slowly add reserved milk, parsley, salt and pepper.

Bring sauce back to the boil while stirring until sauce thickens.

Pour over the fish.

Boil potatoes in salted water.

Mash potatoes with milk or cream, butter and pepper.

Cover fish with the mash and smooth over with fork.

Sprinkle over grated cheese, bake for 20 - 25 minutes

Serve with fresh garden peas and crusty bread.