 Once they are soft, the beans are blended, and added to a pot filled with water and with pork bones to serve as the base of the soup.Once the soup base has taken a chocolate color and has boiled enough, the bones are removed, and water is added to the pot, along with the rest of the ingredients, which may include yuca, green plantains, eggs, and many other ingredients.The soup is served with rice and tortillas, and may be accompanied with sour cream, smoked dry cheese, avocados and lemons.