You will need
Double the little tail ends of the fillets over (about 8 cm) and tie them with cotton string to ensure even thickness of the whole fillet. Rub the meat with olive oil and a mixture of Garlic Pepper Seasoning and Meat Spice Leave to rest at room temperature for 30 minutes. Adjust the oven rack to the middle position. Preheat the oven to 200ºC.
Preheat a ribbed cast iron griddle pan until very hot (no oil in the pan). Put the oiled and seasoned fillets on the smoky hot surface and press flat to emphasise grill marks. Do not turn until browned. Turn and brown very lightly on second side.
Place the pan with the fillets on in the oven. Bake for 5-6 minutes at 200ºC, depending on the thickness of the fillets. Remove to a warm serving dish and rest for 5 minutes. Slice into 1cm thick slices on the diagonal.
Decant the gravy into a microproof sauceboat, add the leftover meat juices and microwave for 1 minute on high. Stir through and if not hot enough give it another 30 seconds.