Preheat a heavy fry pan (cast iron is ideal) over medium high heat. Pat the steak dry with paper towels on both sides. Season generously with salt.
When the pan is hot, add a generous drizzle of oil. Add steak and cook for 30 seconds. After 30 seconds, flip to the other side and cook for 30 seconds, then flip again. Continue flipping, cooking 30 seconds each side.
When the steak has developed a brown crust, after 3 to 4 minutes of total cooking for a 2.5cm steak, remove from pan and check for doneness. Use a meat thermometer and follow these temperatures according to your preference: 54 degrees C = Rare; 60 degrees C = Medium rare; 68 degrees C = Medium; 73 degrees C = Well done.
When your steak is at the desired temperature, remove from pan and let rest for 5 minutes before serving.