Combine beef broth, soy sauce, garlic, cumin, chili powder and ground red pepper in a resealable plastic food storage bag; knead bag to combine. Add beef and seal. Refrigerate up to 24 hours, turning occasionally.
Remove beef from marinade; discard remaining marinade. Grill beef over hot coals 7 minutes per side or until desired doneness. Grill bell peppers and onions 7-10 minutes or until tender, turning once.
Slice beef and serve with bell peppers, onions, tortillas, sour cream and salsa.