In a large pot, add 1/2 cup broth, celery, onion and garlic. Saute until onions are translucent.
Add chicken breasts, canned tomatoes and chili seasoning. Simmer on low heat for 45 minutes.
Remove chicken breasts and shred with a fork. Add shredded chicken back to the pot and cook an additional 5 minutes.
Serve with a dollop of yogurt and fresh cilantro.