Kombu is a type of kelp or seaweed that can improve the digestibility of beans and legumes. It can be found in some grocery and most "health food" stores.
After soaking beans, discard the soaking water and combine about two quarts of fresh water with the beans, enough to cover them by an inch. Add Kombu, if using, to increase digestability, and simmer on medium-low heat. Add tomato sauce, salsa, chili powder and optional vegetables and simmer 60–90 minutes or until beans are soft and most of the water has cooked off. Salt at the end so beans may soften properly. Serve and enjoy.