Place chicken breasts into the bottom of the slow cooker.
Add tomatoes, beans, chicken stock, onions, garlic, and corn to the slow cooker.
Add seasonings and stir. (Do not re-use the spoon you just used because there is raw chicken in the slow cooker.)
If your chicken breasts are frozen, cook on high for 3 hours, then reduce to low. If they’re not frozen, cook on low. Total cooking time should be about 5-6 hours.
About 30 minutes before you’re ready to serve, prepare the yellow rice according to package instructions.
Remove chicken breasts from slow cooker. Use a fork to shred the meat, return to the slow cooker, and stir.
Serve soup over rice. Garnish with Monterey Jack cheese, tortilla strips, and sour cream.
I used frozen chicken breasts that had been marinated in Italian dressing because I didn't have any plain chicken breasts. I usually keep frozen chicken in various marinades in my freezer. If you don't feel like marinating, just skip that step.