Salt, to taste Rinse beans and discard any stones. In a large pot, soak beans overnight in water with baking soda, oregano, cumin and green pepper. The next day, add onion, garlic, olive oil, cider vinegar, sherry and salt to the water and cook on medium-low heat for about 3 hours or until the beans are very tender and liquid is reduced and somewhat thickened. Make sure liquid in pot does not entirely boil away. To prevent beans from burning, add more water when necessary.