Combine first 3 ingredients; rub over both sides of steak. Place steak on a broiler pan coated with cooking spray; broil 4 minutes on each side or until desired degree of doneness.
While steak cooks, arrange 3 cups lettuce and 2 tomato slices on each of 4 plates. Divide red onion slices evenly over tomato.
Slice steak across grain into 1/4-inch-thick slices; divide steak evenly over onion slices. Sprinkle each serving with 1 1/2 teaspoons cheese. Drizzle each serving with 2 tablespoons vinaigrette.