Pick over beans and discard any small stones. Cover them with 2 quarts water and remove any floaters. Soak beans for 4 to 8 hours or until water has penetrated to the core of beans. Drain water, place beans in a 4 quart saucepan and cover with another 2 quarts water. Bring to a boil, reduce heat and simmer, stirring occasionally, for 2 to 4 hours or until beans are quite soft but not falling apart. During the last hour of cooking heat vegetable oil in a saute pan, add onion, garlic and chipolte peppers and saute until onion is translucent. Add vegetables to simmering beans along with salt and pepper to taste. If eating as is, add cilantro.