PREHEAT barbecue to medium-high heat. Mix dressing and soy sauce. Pour half of the dressing mixture over steak in shallow dish; turn to evenly coat both sides. Let stand 10 min.
MEANWHILE, poke small holes in bottom of disposable aluminum foil pan; set aside. Prick potatoes with fork. Microwave on HIGH 10 min. Place potatoes in prepard pan. Add asparagus and rosemary; mix lightly. Add remaining dressing mixture; toss to coat.
REMOVE steak from marinade; discard marinade. Place steak, corn and foil pan on grate of barbecue. Grill 15 min. or until steak is medium doneness (160ºF) and vegetables are tender, turning steak and corn, and stirring vegetables in pan after 8 min. (Corn husks will be blackened.)
serving size = 1/4 recipe (440 g)