Ingredients

4 medium potatoes

4 tablespoons flour

Butter

Milk

Salt and pepper

2oz butter extra

10oz cooked tuna

Juice of 1 lemon

Method

Boil potatoes in salted water until tender, drain and mash with butter and a little milk. Melt extra butter in saucepan, stir in flour and cook 1 minute, remove from heat, gradually stir in 1 pint milk and return to heat. Cook stirring until mixture boils and thickens. Drain tuna and break into large pieces, add tuna to sauce, season lightly with salt and generously with pepper and lemon juice. Line casserole dish with mashed potato, then spoon tuna mixture into dish, top with tomato slices, grated cheese, dot with butter. Bake in hot oven 20 minutes or until golden brown.