Spray a slow cooker insert with olive oil spray and add chicken breasts followed by remaining ingredients, except parmesan cheese.
Cook for 3 1/2 hours on high.
Remove chicken breast, shred or chop, and add back to the pot. Give it a good stir and serve.
Garnish with fresh parmesan cheese.
Notes
*For best flavor I recommend using regular, not low-sodium, chicken broth. Sodium content varies by brand, so you may have to adjust seasonings to your taste preference.