Place the beans in a large saucepan, and cover with an inch ofwater. Place over high heat, and bring to a boil. When the beanshave come to a boil, drain, and return them to the same pot. Coverthe beans with 2 inches of water, and stir in 1 tablespoon of garlic,the tomato, cumin, and chili powder. Bring to a boil over high heat,then reduce heat to low, and simmer until the beans are very soft,about 3 hours and 45 minutes, adding water as needed.Once the beans have cooked, mash them with the remainingtablespoon of garlic, the oil, and salt to taste; use additional wateras needed to achieve desired consistency. Place over low heat for30 minutes, stirring occasionally. Serve.