Heat 1 tablespoon of the oil in large skillet on medium heat. Add onions; cook and stir 10 minutes or until tender. Remove from skillet; keep warm.
Sprinkle Seasoning evenly over both sides of steak.
Heat remaining 1 tablespoon oil in same skillet on medium-high heat. Add steak; cook 2 to 3 minutes per side or until desired doneness. Let stand 5 minutes before slicing. Serve steak slices topped with onions.