Preheat an air fryer on 400ºF for 5 minutes.
Remove the steak from the packaging. Brush all over with the oil. Season generously with salt and pepper, and any other seasonings. Use at least 50% more seasoning than you normally would for a thawed steak.
Place the steak in the air fryer and cook until an instant-read thermometer stuck into the thickest part reads 120ºF to 125ºF for medium rare, 8 to 12 minutes, flipping the steak halfway through.
Turn off the air fryer and open the door so that there’s about a 1-inch opening; let the steak rest for 5 minutes. Transfer the steak to a cutting board and slice against the grain. Sprinkle the steak with flaky sea salt and serve.