Combine first 7 ingredients in a large zip-top bag; add steak. Seal and marinate in refrigerator 8 hours or overnight, turning bag occasionally. Remove steak from bag, reserving marinade.
Place steak on grill rack coated with cooking spray; grill 5 minutes on each side or until desired degree of doneness. Let stand 10 minutes. Cut diagonally across grain into thin slices.
Combine reserved marinade and cornstarch in a saucepan. Bring to a boil; cook 1 minute, stirring occasionally. Drizzle steak with 1 tablespoon of sauce before serving.
Core (+ Pts. for Brown Sugar)
Great with Garlic-Chive Mashed Potatoes. The sauce is really intense, you only need the 1 tablespoon suggested.