Wash and drain pinto beans and soak in water overnight. Bring to boil, lower heat, and simmer 2 to 3 hours or until tender. Drain. Meanwhile, melt butter in large skillet and add onions, chilies, and garlic. Saute until onion is soft. Add chopped sirloin and cook over moderate heat until meat is brown. In a separate pan brown sausage and pour off fat. Add sausage to meat mixture. Sprinkle with flour and stir to blend, then transfer to Dutch oven or 8 litre kettle. Add pinto and canned beans and all remaining ingredints except sour cream; bring just to boil. Lower heat and simmer about 30 minutes. Skim off fat with a cold spoon as it rises to the top. Serve with sour cream. This freezes wonderfully.