Add all ingredients into the crock pot, with the chicken going in last. Press down chicken until it is just under the other ingredients. Cook on high for 3-5 hrs.
5 hrs into cooking (depending on if your chicken was thawed and your slow cooker's heat), remove chicken from the soup base. Allow to cool a bit and then shred the chicken. Do this by slicing across the grain of the meat. Chicken that is cooked enough will fall apart. If not shredding easily, return chicken to pot for a little longer.
Return fully shredded chicken to the pot, turn down heat and cook for another hour.
After dishing out soup, top off with shredded cheese and tortilla chips.