Flemish Soup

Put an equal quantity of carrots, onions and turnips cut into small pieces in a
saucepan, with a head of lettuce, two leeks, a head of endive, a little chervil and a
lump of butter, one-half pint of either mutton or beef broth; boil all gently till tender,
stirring now and then, then pour in two quarts of boiling broth, season it with pepper,
salt and sugar and let it simmer for two hours. Beat the yolks of three eggs with
one-half pint of cream, stir it in with the soup, turn into a tureen and serve.