Leave steaks at room temperature for at least 30 minutes before preparing or cooking it. Use this time to prepare your cast iron skillet. Place it a hot oven to get it very very hot.
Once steaks have come to room temperature, pat the steaks dry with paper towels.
Generously, season the steaks on both sides with the salt and pepper.
Place pan cast iron skillet or stainless steel pan, over medium-high heat until it’s VERY hot.
Add the oil to the pan and heat until it begins to shimmer and move easily around the pan, about 1 minute or so.
Carefully place the steaks in the pan away from you so oil doesn’t platter in your direction. If you hear sizzle after you place your steak in the pan, that’s a great thing. It means that your pan was hot enough for pan searing restaurant style steak.
Avoid flipping steaks to early or fiddling with them. After about 3-4 minutes or until a deep golden crust forms, flip the steak over to the other side.
During the last minute or two of cooking your steaks, add the butter , garlic, and rosemary sprigs to the pan with the steaks. Using a spoon, scoop melted butter over steaks.
Once desired doneness is reached, transfer onto a place, cover with aluminum foil and let it sit 5-10 minutes before cutting. This will ensure the juices don’t leak out and dry out your steak.