Begin by placing your cast iron skillet on the stove over medium-high heat. Allow it to heat up for about 5 minutes.
While the skillet is heating, take your frozen porterhouse steak out of the freezer. Generously season both sides with kosher salt and freshly ground black pepper.
Once the skillet is hot, add a tablespoon of safflower oil and swirl it around to coat the bottom of the skillet.
Carefully place the seasoned frozen steak in the skillet. Sear the steak for about 3-4 minutes on one side without moving it.
Using your tongs, gently flip the steak over. Sear the other side for an additional 3-4 minutes.
Insert a meat thermometer into the thickest part of the steak. For medium-rare, you’re looking for a temperature of about 130°F.
Once cooked to your liking, remove the steak from the skillet and place it on a plate. Cover it loosely with aluminum foil and let it rest for at least 5 minutes.
After resting, slice the steak against the grain and serve it up with your favorite sides.
