keep steak at room temperature for 1 hour sprinkle generously with salt. Then place the steak in a large baking sheet together with garlic cloves and rosemary branches (if not available use dried rosemary)
cover the steak well inside the baking sheet and staple the sheet around to seal it then cover with aluminum foil. Bakeiin the over on 150 deg c for 45 mins.
open the sheet and aluminum foil keep the renderings in the side for use as a saucem
place in cast iron and sear on charcoal or oven top.
slice and dip in rendering sauce.