Instructions

  1. In a slow cooker, combine the beef, green peppers and onions.
  2. In a small bowl, combine tomato paste, brown sugar, vinegar, chili powder, salt, worcestershire sauce and mustard.
  3. Stir into meat mixture.
  4. Cover and cook on high for 7-8 hours or until meat is very tender.
  5. Skim fat from cooking juices.
  6. Shred beef using two forks.
  7. With a slotted spoon place about 1/2 cup beef mixture on each bun and serve.