Mince the chicken, mix in the taragon, lemon rind and pepper. Beat in the egg white, form the mixture into small balls using your hands.

Place the butter, flour, milk and crumbled stock cube in a saucepan, heat stirring until the soup boils, thickens and is smooth, add pepper to taste.

Drop in the chicken balls and boil for 4-5 minutes.

Just before serving add watercress leaves to the soup. Serve hot with brown bread.