Start heating your cast iron skillet for about 10 minutes on high.... Skillet should be bare! Get yourself some Paul Prudhomme's Blacked Redfish Magic... Melt a pat of butter... Spoon some on one side of the steak and apply Blackened Redfish Magic liberally.... Then the opposite side. With your cast iron skillet WAY Hot... Drop in the steak. Time it per your liking... But only flip it ONCE!
This produces HUGE volumes of white smoke... So disable your smoke detectors or take a hot plate outside! I've done it inside before but only when I was out of gas on the grill and desperate!
The flavor of the steak cannot be beat unless you flame grill!