Stir the milk and cornstarch together and beat in the egg yolks. Set aside. Bring the stock to boil in a 4 litre soup pot and add the rice. Cook, covered, until the rice is puffy and tender, about 25 min. Remove the soup form heat, add milk and egg mixture, stirring carefully. Continue to cook for a moment until all thickens. Remove from the heat again and add the butter, chopped parsley, and lemon juice. You may wish to add some grated lemon peel as well. ----