In a slow cooker, add chicken and season with taco seasoning packets.
Add chopped onion, bell peppers and chipotle peppers.
Stir in diced tomatoes, Rotel, tomato paste and chicken broth without disturbing chicken on the bottom. Add beans and give a quick stir. (If using Ranch Style beans, I add whole can with juice. If using black beans or pinto beans, drain and rinse.)
Cook on high for 2 hours. After a couple hours of cooking, remove chicken, shred and return it to slow cooker. Cook an additional 2 hours.
Soup should be done after about 4 hours on high or 6 on low. Although slow cookers cook at varying speeds so be certain chicken is cooked thoroughly.