Remove your steak from the packaging, pat dry and bring to room temperature. Pre heat your griddle or heavy based frying pan until it sizzles when drop of oil is added. Season the meat with salt just prior to cooking. Massage the steak with a little duck or goose fat, creating a very thin layer over the meat. Don't overcrowd the cooking base. Cook over high heat turning the steak only once. After a rich, golden crust has formed, reduce heat to medium. Cook the steak for 7 to 8 minutes then turn and cook the reverse side for 5 to 6 minutes for medium rare. Alternatively, after searing the meat on the top of the stove, cook the steak in a pre-heated oven at 200oc for 8 to 10 minutes. Finish by adding a large knob of butter to the pan and baste the steak for a minute or two by spooning over the melting butter to enrich it. Leave to rest in a warm place at least 7 to 8 minutes before carving