Dice chicken into 1/2 inch cubes.
Season chicken and cook in skillet until browned and cooked through.
Remove chicken and place in the bottom of a crockpot.
In the same skillet, add 1 tablespoon of oil and heat to medium.
Chop/dice bell pepper into 1/4-inch cubes.
Cook bell pepper in oil until edges start to brown.
Transfer bell pepper and pan bit to the crockpot.
Drain and rinse canned beans and add to crockpot.
Add all remaining ingredients to crockpot, except spinach.
Let the soup cook in the crockpot for at least 4 hours (this could also simmer in a dutch oven for 1 hour, instead.)
Chop spinach and add to soup 20-30 minutes before you eat it.
Serve hot and garnish with cheese, chips, avocados or more salsa.