Wash beans thoroughly, then soak overnight in cold water. Be sure to cover beans. To cook, pour off water and add fresh water to cover. Add salt pork and bring to a boil in covered pot. Turn flame down to slightly higher than low and cook one and a half hours. Add onions, peppers, garlic and salt. Cook three hours. Add tomato sauce and cook an hour and a half more, adding water as necessary. Beans and meat should always be covered with liquid.