Leave the meat to return to room temperature before cooking.
Add the beef tallow to a frying pan and cook on low heat to release the oil. Then raise the heat to high. Season the steak with salt just before adding to the pan.
When the meat has browned on the underside (this will be the top side when served), flip it over and brown the other side. Season with pepper.
Once both sides have browned, sink the bottom of the pan into a bowl of water for 2-3 seconds to cool. Put the pan back on low heat and cook for a further 3 minutes. This will determine how done your meat gets.
Place the steak on a chopping board to cool and let the juices rest for 3 minutes.
This method should leave you with a steak that is cooked like this in the middle. It has heated all the way through, giving it a fantastic flavour.
Story Behind this Recipe
I keep uploading really simple recipes, which is a little embarrassing, so I have decided not to call this a recipe. Although this isn't really a recipe, teaching people how to cook is also very important.
Of course the colour of the meat is important, but cooking the meat through to the middle is what will draw out the best flavour. Japanese beef doesn't really get tough, so it's probably better to overcook than to undercook.