In a large saucepan or soup pot with cover, combine chicken stock, bouillon, carrots, potatoes, and celery. Bring to a boil, reduce heat, and cook covered, over low heat, until potatoes start to get soft (about 10 minutes). Do not overcook. Add pickles and continue cooking about 15 minutes. In a small bowl, beat milk and flour until smooth and stir in a small amount of the hot soup (to temper) and add to soup. Bring to the boil and cook until slightly thickened. Remove from heat. In a small bowl, beat egg with sour cream until smooth and stir in a small amount of the hot soup. Add to soup and stir until smooth. Keep soup warm but DO NOT BOIL (the soup will curdle). Add salt and pepper to taste and garnish with parsley and dill. Makes 10 servings.