Ham & cheese casserole
Preheat the oven to 180°C/ 350°F/Gas mark 4.
Season the flour with salt and pepper. Melt the butter in a saucepan, then add the flour mixture. Cook over a medium heat for 1 minute, stirring constantly. Remove from the heat and stir in the milk. Return to the heat and cook until thick.
In a very large bowl, mix the remaining ingredients with the sauce. Bake in a casserole dish for 1 1⁄2 hours, keeping the casserole covered for the first 30 minutes of cooking. Allow to cool for 15 minutes before serving.