In a large skillet over medium high heat, heat oil and butter. Roll pork in flour and saute in the hot oil until pork is just browned. Add pork and all the scrapings from the skillet to the slow cooker. Add all remaining ingredients to the slow cooker except for the sour cream. Cover and cook on low setting for 8 hours. Stir sour cream into hot meat mixture about 10 minutes before serving. Serve over hot cooked noodles.