Grate orange peel; remove remaining peel and pith. Separate orange into segments. In a bowl, combine grated peel, orange juice, teriyaki sauce, mustard, honey, garlic and pepper. Cut beef into 1-in. cubes; place in a resealable plastic bag. Add oranges, mushrooms, onions and half of marinade. Seal bag; refrigerate overnight. Refrigerate remaining marinade for sauce.
Drain and discard marinade. On four metal or soaked wooden skewers, alternately thread beef, oranges and vegetables. Broil 3 in. from the heat for 15-20 minutes or until meat reaches desired doneness and vegetables are tender, turning often.
In a saucepan, combine cornstarch and water until smooth. Stir in reserved marinade. Bring to a boil; cook and stir for 2 minutes. Serve over kabobs and rice. Yield: 2 servings.