Throw all the ingredients in the crockpot except the cheese and sour cream. You can throw in the raw or frozen chicken as is. Let it cook 6-8 hours. Shred the chicken with some forks before serving. Garnish with cheese, sour cream, and tortilla strips.
Recipe by Honeybear Lane at https://www.honeybearlane.com/2013/04/crockpot-chicken-tortilla-soup.html