Polish Sorrel Soup

Ingredients:
• ½ lb. sorrel
• 1 Tbls. Butter
• 3 Tbls. Water
• 4 cups broth
• 3-4 Tbls. Flour
• 2 cups milk
• 2 raw egg yolks
• 1 Tbls. soft butter
• salt and pepper, to taste
Chop sorrel, and add to a skillet along with 1 Tbls. Butter and 3 Tbls. water. Simmer on low heat under cover for 10 minutes.

Force mixture through a sieve into 4 cups broth and simmer a few minutes longer. Dissolve 3-4 Tbls. flour in 2 cups milk and add to the pot. Simmer briefly, then remove from heat. Fork-blend 2 raw egg yolks with 1 Tbls. soft butter, adding several tablespoons of the soup and stirring until smooth. Add back to the pot. Add salt and pepper, to taste.
(from: http://www.netcooks.com/ recipes/Soups/Zupa.Szczawiowa.(Sorrel.Soup).html)