Place the chicken breasts, onion, green pepper, enchilada sauce, undrained tomatoes, and rinsed/drained black beans, undrained corn, chicken stock, and minced garlic into a large crockpot. Add all the seasonings, stir, and cover. Cook on high for 3-5 hours (a little longer if using frozen chicken breasts--that's what I use!), or low for 5-8 hours, or until the the chicken will shred easily with a fork. Once the chicken is tender, remove it from the crockpot and place in a large bowl, then use two forks to shred it.
Soften the cream cheese--it should be very soft--and cut into cubes. Place them inside the crockpot and stir well. Put the cover back on and let it melt for a few minutes, then open it again and use a whisk to thoroughly combine the cream cheese with the other ingredients.
Add the chicken back into to the crockpot, stir, put the cover back on, and cook on high until all the cream cheese is melted--usually around 20 minutes or so. Whisk again!
While you're waiting for the cream cheese to melt, it's a great time to make the quesadillas and get all the toppings ready.
Serve the soup into bowls, and top with your favorite ingredients--cilantro, lime, green onion, cheese, guacamole, and sour cream. Instead of a quesadilla, you can do tortilla strips if you prefer.