Take 1lb leeks, 4 rashers bacon, 4oz butter, 1 pint milk, Cornflour, Salt and pepper (to taste). Chop bacon into strips and gently fry in butter in a closed pan. Clean the leeks, chop and add. Cook gently until very tender (20 mins). Add the milk, salt and pepper (if required) and heat without boiling. Thicken with cornflour if desired. Serve topped with grated cheese.