Combine chicken breasts, onion, garlic, tomatoes, broth, salt, pepper, and green chili in your crockpot. Cook on high for 6 hours, then low until ready to serve. Shred chicken with two forks.
**To make on the stovetop, cook your chicken first, then shred and add to the soup ingredients. Cook over medium heat until the soup is heated through. You can also use a roast chicken from the grocery store instead of chicken breasts. You'd only need time for the soup to heat through in a pot on the stove,
Serves 6. To serve, in each bowl place a layer of cheese (whichever kind you like best–I love both of them!), then spoon the soup on top. Sprinkle with tortilla strips, cilantro, and avocado. Serve with a dollop of sour cream as desired.
*For my family of 8, I usually double this recipe. I also add extra beans to bulk it up a little, and even add an extra chicken breast. The ingredients can be forgiving--if you like extra of something, add it in!