Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
                        -----meatballs-----
   1      cup           white bread -- crusts trimmed
   2      pounds        lean ground beef
   3      tablespoons   onion -- chopped
   1      tablespoon    parsley -- chopped
   1      tablespoon    mint -- chopped
   2                    eggs -- separated
                        salt and pepper to taste
                        flour
                        oil or butter for frying
                        -----the sauce-----
     1/3  cup           butter
   3      bunches       scallions -- white part only>>
                        cleaned and chopped
     1/2  cup           white vinegar
   2      cups          hot water
     1/2  cup           cold milk
   1      tablespoon    cornstarch

Preparation:

Wet the bread with cold water and squeeze out the excess; mix well with the chopped meat. Add the onion, parsley, mint, egg whites, salt and pepper. Shape meatballs, flour lightly; fry in fat. TO MAKE SAUCE, brown the butter in a saucepan; add scallions; sauté until golden. Add vinegar and water, cook until only half the liquid remains. Beat egg yolks very thoroughly in bowl. In another bowl, mix cornstarch in milk, add this mixture to the egg yolks, then blend in some liquid from the pot, beating all the while. Pour egg mixture over meatballs, shaking pot gently until sauce thickens.