In a slow cooker place chicken breast, garlic, black pepper, parsley, dill, lemon zest, onion, carrots and chicken broth.

Cook for 5 hours on high or for 8 hours on low

Add orzo pasta and cook for one additional hour (on high).

Remove chicken breast from slow cooker and shred or cube.

Place the chicken back in the slow cooker, add in lemon juice, celery, and salt to taste. Stir and let cook on high for 1 more hour.