I trim the steak into the smaller sizes you can see in the before photo, getting rid of any gnarly bits in the process then cook it before anything else. Cast iron pan, really hot, lightly season the steak and let it char on all sides without taking it too far. I move it round the pan each time it’s turned so the pan doesn’t over-smoke and the steak chars that bit quicker without cooking through. I then rest the steak, wrapped in foil, somewhere that isn’t cold while I cook everything else. Hopefully the steak is perfect when I come to slice and serve it but if it’s a little under then I stir it in with the onion etc for a couple of minutes after it’s been sliced.