This is how I’ve done it for the past ten years, but the recipe skips the prep, which can be some of the most important steps:
1. let the steak set at room temperature for an hour, minumum. You don’t cook a cold steak.
2. Apply the kosher salt to each side of the steak as it sits. This will draw water out of the surface of the steak (so it doesn’t steam-cook in the cast iron pan). Blot off the water with a paper towel every now and then, because you want a DRY steak on your pan. The salt also makes the surface proteins sticky, so they brown easier.
I never knew the reason for the salt—thanks for this.