Rinse beans well, cover with cool water, and soak for 2 hours. Drain. Put the beans in large pot with the chicken stock and bring to a boil over high heat.
In a saucepan, heat the butter over medium heat. Add the garlic, onion, and chiles and saute for 5 minutes. Add chile mixture to pot with beans. Add the chicken, cumin, oregano, pepper, white pepper, red pepper flakes, and cilantro. Lower the heat to medium and cook, stirring occasionally, for approximately 1 1/2 hours. Serve with cornbread, if desired.