This is for ZamZ
It is best to use a good seasoned cast iron skillet as they retain and conduct heat exceptionally well. A non-stick pan will do, but they warp over time if you use them on high heat.
The cut of steak is very important. If possible, use sirloin caps, tenderloin, New York cut, or such. ZamZ had a rump steak though, so we'll talk about that.
Any steak benefits from a marinade. This could be made with a bit of extra virgin olive oil, minced garlic, roughly crushed black or green peppercorns, a few drops of sesame oil. The steak should marinate at least for half an hour. For a tougher cut, even three hours is not too long. If you are going to marinate for a short period, then some shoyu (soy sauce) is a good addition. Do not soak in shoyu for too long or use salt however because this will draw moisture from the meat and cause it to dry out and toughen up.
When you are ready to cook the steak, preheat the skillet until it smokes or the non-stick pan until it seems really hot. Pour in a small quantity of the oily marinade and place the steak in the pan. Always put things in hot pans with your hand moving away from the body to reduce spurts of hot oil that could burn you.
Sear the steak on the first side for two to three minutes. With a pair of tongs, pick up the steak and flip it to the other side. The first side should have some charring.
About tongs. Always use tongs. Never use a fork to cook meat with. You will puncture it and lose the juices. Never cut into a steak to test for doneness. Press on the surface of the meat with the tongs and notice the resistance. Soft is raw to rare, firm is medium, hard is well-done (which is a terrible thing to do to steak).
After one minute, pick up the steak with the tongs. Hold it firmly and sear the four edges for around half a minute or a minute.
Put the steak back on its first or second side, whichever requires more charring for about half a minute.
Remove the steak and put it into a shallow bowl. Let the steak rest for at least ten minutes, preferably fifteen or twenty. It will continue to cook for a while and juices will escape. As the steak cools, the fibres shrink back and retain the rest of the juices.
While the steak is resting, pour off the fat from the skillet and return it to high heat. Scrape the fond, the burnt bits on the bottom of the pan. These are very rich in flavour. (If you are using a non-stick pan, use a wooden spoon.) Pour in a cup or so of red wine and a few drops of balsamic vinegar. Stir the fond into the wine and let the wine reduce by half or two thirds.
Pour this sauce into a bowl for dipping or to ladle over roast potatoes. Add the juices around the steak from the bowl.
Transfer the steak to a wooden cutting board. Hold the steak at one end with your fingers. With a very sharp knife (I recommend Wusthorf-Trident or Henkel) slice the steak into extremely thin pieces. Slide the knife under the steak and gather all of the pieces together, holding it from the top with the other hand.
Transfer to a plate or platter that has been strewn with mesclun or other greens. Now would be the time to season, preferably with coarse sea salt and fresh black pepper.
Serve with the dipping sauce and perhaps a bit of Dijon mustard in another bowl. Roast potatoes, rice, crusty breads are all good accompaniments.
Served this way, a single steak will be enough for two people. So you can afford to buy a good cut. Don't be cheap. You're worth the expense.