Salt flat iron steaks on both sides. Leave at room temperature for 45 minutes. Spray a rimmed baking sheet with cooking spray
Preheat the broiler. Pat steaks dry and lightly coat them with olive oil. Sprinkle black pepper and salt on flat iron steaks. Place steaks on the baking sheet and move them into the oven directly underneath the broiler. Cook for 5-6 minutes on each side
Rest on a foil-tented plate for 5-10 minutes