Let steak sit at room temperature 30 minutes to an hour before cooking.
NOTE: If you just remembered those steaks were in the fridge and you really need to get dinner on the table, don’t fret about this step—your steak will be just as delicious.
Pat steak dry with paper towels, coat lightly with oil, then season the steak very generously with salt and pepper.
Heat a thin layer of vegetable oil in a castiron skillet over high heat until the oil is just starting to smoke. Add steak to the hot skillet and cook until a brown crust starts to form on the underside of the steak, about 1 minute. Flip steak over and cook 1 minute more. Continue flipping every 30 seconds until a nice crust forms, about 4 minutes.
Add butter and herbs (if using) to the skillet and continue to cook, basting the steak with the pan juices and flipping the steak often until an instant-read thermometer inserted into the thickest part of the steak registers 120° to 125°F for medium rare, or 130°F for medium. Steak should be medium rare at this time ... continue to cook a minute more on each side for medium.
Transfer steak to a plate or cutting board and pour pan juices over. Allow the steak to rest for at least 5 minutes before serving or slicing.