In a large skillet, brown beef in oil; drain. Transfer to a 1-½-qt. slow cooker. Combine the broth, onion, ketchup, Worcestershire sauce, brown sugar, paprika and mustard. Pour over beef. Cover and cook on low 8-10 hours or until meat is tender.
In a small bowl, combine flour and water until smooth. Gradually stir into beef mixture. Cover and cook on high until thickened, about 30 minutes longer. Serve with noodles. If desired, sprinkle with parsley.
