of water, and soak overnight. Add remaining 4 cups water to Dutch oven; cover and bring to a boil. Reduce heat, and simmer 2 1/2 hrs or until beans are tender. Combine remaining 2 tb onion, garlic, oregano, and cumin in a small bowl; mash mixture, using a fork. Stir in vinegar. Add vinegar mixture and salt to beans. Simmer, uncovered, an additional 20 minutes. Serve over hot cooked rice.