For the best results it is necessary to use wood charcoal grill oven, but the casting iron skillet will do the job as well. Preheat iron skillet with heavy lid to about 280 ° C. Usually it is possible to check the temperature by the drop of vegetable oil, it should start smoke.
Place thyme on to the skilled and cover it with the rump steak. Always cover with lid (not on the picture) during frying. For 3/4 inch thick steak, it is optimal to fry about 1.5-2 min on each side twicely, to have a medium-rare to medium doneness.