- Rub seasoning generously onto all sides of flank steak. Let sit 5 minutes; repeat.
- Spray COLD grill with nonstick cooking spray. Heat grill to medium-high heat. Grill steak 5 to 7 minutes on each side, creating a ‘crust’. Lower temperature to medium-low and continue grilling 5 to 10 minutes until desired doneness is reached. Remove from grill; tent with foil for 10 minutes.
- Drizzle olive oil over onions. Place onions on grill and cook 5 to 7 minutes; turning once. Onions will be slightly caramelized and crunchy. Remove from grill; chop.
- Divide lettuce evenly among plates. Slice flank steak thinly on the bias; evenly distribute on salads. Sprinkle with onions, tomatoes and blue cheese crumbles. Toss with desired amount of red wine vinaigrette.
Large, thick slices of onion work best for grilling.