Drain mandarin oranges, reserving syrup. To syrup, add teriyaki sauce, corn syrup, corn starch and crushed red pepper; set aside.
Heat 2 tablespoons oil in a large skillet over medium-high heat. Add broccoli; stir fry 2 minutes or until tender crisp. Remove from skillet.
Add remaining 1 tablespoon oil to skillet. Add half the beef and stir fry just until browned. Repeat with remaining beef. Remove from skillet.
Add teriyaki sauce mixture and broccoli to skillet; heat to boiling. Stir in beef and oranges; heat through.
Serve over rice, if desired.