1. Place the beans in a bowl or pot, cover with cold water and allow to soak overnight. Drain and rinse before proceeding. (Alternatively, add the beans to a medium pot and cover with hot water. Bring to a boil, and then boil for 2 minutes. Turn off the heat, cover the pot and allow the beans to sit for 1 hour. Drain the beans and rinse them with cold water before proceeding.)
2. In a medium pot, add the soaked beans, chicken broth, 2 cups water, the garlic, onions and green, red and yellow bell peppers. Bring to a boil, reduce the heat to low, cover and simmer for 1 1/2 hours.
3. Then add the chilli powder, cumin and salt and stir. Cover and continue simmering until the liquid level is to your liking, about another hour. Taste for seasoning and add more of what it needs.
4. Serve in a bowl with sour cream, coriander, lime wedges and diced bell peppers on the side.