Wash beans; place in a large pot and cover with water. Add salt and soak overnight. Early the next day add onions, green peppers, garlic, oregano and bay leaves. Bring to a boil and reduce heat to simmer. Simemr on low heat all day, stirring often. When beans are medium soft add olvie oil. Cook until thick and beans are done. At this point you may add more salt, if desired. With a fork, remove green pepper skins and bay leaves. Serve over rice. Serves 4 to 6. Note: Fresh chopped onions are usually sprinkled over black beans. This freezes well. Reheat on very low heat.