If using dried beans, combine beans and onions in a pan in preheated water.
Bring to a boil for 2 minutes. Cover and remove from heat for 1 hour (or soak beans in cold water overnight).
Return to heat, bring to a boil; simmer slowly until beans are very tender, about 3 hours.
Mash cooked beans with a potato masher, and add the bacon dripping, butter or lard. Mix well; continue cooking, stirring frequently until beans are thickened and fat is absorbed. Season and add chili powder to taste.
Allow to stand until cool and either serve cold or refried