1. Rinse chicken bones and flanken, and pat dry. Place chicken bones on the bottom of a large pot, and add the rest of the ingredients, placing the flanken, dill, and parsley on the top. Cover with water. Add salt and fresh black pepper. Bring to a boil.
2. Cover and simmer for a minimum of eight hours. If you prefer, you can skim off the fat after the soup is refrigerated prior to reheating. Also, if you prefer a super-clear broth, put the soup through a strainer. When the soup is ready to be served, remove dill and parsley and discard.
3. Garnish each bowl of soup with pieces of carrots and zucchini.