Its one of my favorite meals.
It is easy to fix. You want a thick steak 1.5 to 2 in take it out before cooking let it get to room temp and coat it with what ever you plan on using as a blackening Coating. You can use Creole seasoning
Old bay blacking add seseme seeds etc . i heat up my olive oil and seseme oul to the point its close to smoking then put the steak on about 2 to 3 min per side depending on thickness . you want the center raw and just the exterior cooked the inside should be hot but not cooked