Most home cooks under-heat their pan. With domestic beef that costs you crust. With A5, it costs you the entire texture — a tepid pan won't render the marbling fast enough, and you'll pull a greasy gray steak instead of a sheeny rare one.
The target
Cast iron, dry, 450°F surface temperature minimum. No oil. No butter. The steak's own marbling will fry it once it hits the pan.
If you have an infrared thermometer, point it at the pan. If you don't, use the smoke test: a thin film of canola tossed in the pan should smoke within 2 seconds of contact, then immediately wipe out. That's your green light.
The cook
- Pat the steak completely dry. Surface moisture means steam, and steam means no crust.
- Lay it down. Do not move it for 60 seconds. You'll hear an aggressive sear, see fat pooling within 10 seconds, smell hazelnuts at 30.
- Flip once. 45–60 seconds on the second side.
- Off the heat. Rest 4–5 minutes on a warm plate, NOT a wire rack — you don't want all that rendered fat to drip away.
Why no oil
A5 puts out enough rendered fat in the first 15 seconds to lubricate the pan. Adding oil on top of that gets you a deep-fried surface instead of a seared one — chewy, not crisp.
Thicker portions
If the cut is over 1.5 inches — a strip steak, a primal slab — reverse-sear it. 250°F oven to 105°F internal, then flash 30 seconds per side in the cast iron. The thin-cube technique above doesn't scale.
