Combine beans, chicken broth, garlic and half of the onions in a large soup pot and bring to boil. Reduce heat and simmer until beans are very soft, 3 hours or more. Add more chicken broth, if necessary. In a skillet, saute' remaining onions in oil until tender. Add chilies and seasonings and mix thoroughly. Add to bean mixture. Add chicken and continue to simmer 1 hour. Serve topped with grated cheese.
(I usually go a bit heavy on the cumin/cayenne... for the chicken I'll bar-b-q with an ancho chili rub.) This goes really well with cornbread. You can also do this in a crockpot. Just put everything in there and turn it on.