Cut beef into bite-size pieces; brown in oil in skillet.
Transfer to a slow cooker.
Cover with water; add tomato sauce and seasonings.
Cover and cook on low for 8 hours, or on high for 4 hours, or until meat is tender.
In a small bowl, combine flour and cold water to make a paste; stir into liquid in slow cooker.
Cover and cook on high 30 minutes longer or until gravy is thickened.
Serve over rice or potatoes.