1. In a large pot over high heat, combine the chicken, water, onion and barley. Bring to a boil, reduce heat to low and simmer for 1 hour. Remove chicken, discard the bones and skin, chop meat into bite size pieces and return to the pot.
2. Add the chicken broth, leeks, celery, thyme, parsley, salt and ground black pepper. Simmer for 30 more minutes, or until all vegetables are tender.