03Prepare barbecue (medium-high heat). Grill steak until cooked to desired doneness, about 5 minutes per side for medium-rare. Using tongs, transfer steak to cutting board. Tent with foil to keep warm. Let rest 10 minutes.
04Meanwhile, spray asparagus and onion slices with nonstick spray; sprinkle with salt and pepper. Grill asparagus until crisp-tender and slightly charred, turning often, about 5 minutes. Transfer asparagus to plate. Keeping slices intact, grill onion until slightly charred and almost tender, about 4 minutes per side; transfer to plate with asparagus.
05Cut steak crosswise into thin slices. Arrange steak and asparagus on 6 plates. Drizzle with vinaigrette. Garnish salads with some onion rings and orange slices.