In a bowl, combine the first seven ingredients. Pour 3/4 cup marinade into a shallow dish; add the beef. Turn to coat; refrigerate, covered, for up to 24 hours, turning once. Cover and refrigerate remaining marinade., Drain and discard marinade. Grill flank steak, uncovered, over medium heat for 6-8 minutes on each side or until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°). , Meanwhile, in a skillet, cook vegetables in reserved marinade until crisp-tender. Thinly slice steak across the grain. Serve with vegetables.