Bring to room temperature and dry all over with kitchen towel. Season lightly with sea salt and pepper.
Take a hot castiron pan and without adding any oil place the steak in the centre of the pan. cook for 1-2 minutes on each side on a high heat to brown and then turn the heat down.
Keep on turning every couple of minutes. The total cooking time should be 10-15 minutes
It will take around 15 mins to get to a core temperature of 40°c. After this the steak should feel slightly springy when pressed.
Remove and cover loosely with foil to rest for around 15 minutes at room temp.
Slice and serve with a good red wine for a wonderful feast.