To prepare dressing, combine first 9 ingredients, stirring until sugar dissolves.
To prepare salad, sprinkle steak with salt and pepper. Place steak on a grill rack coated with cooking spray; grill 4 minutes on each side or until desired degree of doneness. Remove from grill; place on a cutting board. Let stand 15 minutes. Cut steak diagonally across grain into thin slices. Place steak, lettuce, and remaining ingredients in a large bowl. Pour dressing over salad; toss well to coat. Serve immediately.