Ciorba de pui (sour chicken soup)

1 frying chicken, cut up
1 tbsp. salt
1 onion, whole
2 stalks celery
2 black peppercorns
2 pkg. frozen mixed veggies
1 tsp. tarragon, chopped
1 tbsp. parsley, chopped
3 tbsp. sour cream
1 lemon, juice of
3 egg yolks

Cover chicken with cold water in a large pot; add salt and bring to a boil. When foam starts to form; remove as much as possible; lower the heat and boil gently for 15 to 20 minutes. Add whole onion; celery and pepper. Let boil another half hour or until the meat is cooked. Meanwhile, prepare veggies according to package directions. Add to the soup from which you have removed the celery and onion. Add tarragon and parsley and let boil 10 minutes more. In a large bowl beat together the egg yolks, sour cream and lemon juice. Add the soup to this mixture very slowly, just a little at a time. Stir constantly until it is all blended. Do not boil again.