Wash and pick over beans, place in slow cooker, cover with water, and cook - 4-6 hours on High, or 6-8 hours on Low. Drain most, not all, liquid from beans, and return beans to slow cooker.

Trim stems from dried peppers, and discard seeds. Soak in hot water to cover for half an hour, then puree with a little soaking liquid, and set aside. (If they are dry and brittle, you can just grind them as they are, without soaking.)

Chop onions and garlic. Heat oil in saute pan, saute onions and garlic until just browning, not cooked all the way through. If you are using dry chili powder, add to pan now. Add other seasoning to pan, stir and heat. Scrape contents of pan into slow cooker, on top of beans. Add chili pepper puree to pot if using.

Cut beef into bite sized cubes. Heat oil in the same pan, and brown the meat. Place meat in slow cooker on top of onion mixture. Use a little water to deglaze the pan, and scrape that into the slow cooker.

Add tomatoes to slow cooker on top of the rest of the ingredients.

Cook on High 5-6 hours, on Low 7-8.