FRENCH OYSTER SOUP

1 quart oysters.
4 cups milk.
1 slice onion.
2 blades mace.
1/3 cup butter.
1/3 cup flour.
Yolks 2 eggs.
Salt and pepper.

Make as Oyster Soup, adding yolks of eggs, slightly beaten, just before serving. Garnish with Fish Quenelles.