Wash lentils and drain. Cover with cold water and soak for 2 hours. Drain. Cover with water and bring to a boil for 10 minutes. Drain, add beef stock, ham knuckle, and simmer for 2 1/2 to 3 hours or until lentils are tender. Twenty minutes before lentils are done add potatoes. Just before serving melt butter in a small pan and add flour, mixing. Stir this into the soup. Serve.{$7e}(Original recipe for 4)
