Wash well ½ lb. sorrel, trim away stems, chop, add to skillet along with 1 tablespoon butter and 3 tablespoons water and simmer on low heat under cover 10 min.

Force mixture through sieve into 4 cups strained meat stock and simmer a few min. longer. Dissolve 3-4 tablespoons flour in 2 cups milk and add to pot. Simmer briefly, then remove from heat. Fork-blend 2 raw egg yolks with 1 tablespoon soft butter, adding several tablespoons soup and stirring until smooth. Add to pot.