The Grade: The best steakhouses and restaurants serve up the best, most expensive grades of beef. In the United States it is know as USDA Prime. Prime grade beef accounts for nearly 2% of all beef production in the United States. There are similar equivalents in all other countries. The demand for this high quality beef makes it hard for you and I to purchase at a regular grocery store. Since you probably can't find this, look for Choice grade beef for your steaks. It is very, very good, if not the best.
The Aging: Most fine restaurants age their beef to intensify the flavor and improve the tenderness of the cut. Aging is done by letting the meat sit (in very controlled conditions) for several days or weeks. This is a difficult process for the average person to perform because the risk of spoilage and food poisoning can be very high. You can, however, check with your local meat markets to try and find a source for aged beef. If you can't find it, don't worry. You can still get a great steak.
The Seasoning: Great steaks need little seasoning. However, every great steakhouse seasons the steaks they cook. Typically, a steak is seasoned with coarse ground black pepper, sea or kosher salt, parsley and butter. Yes, Butter. We'll get to the butter later, but it finds its way on to a number of steaks, but you have to add it at just the right time.
The Equipment: Most big steakhouses broil their steaks. Yes, there are few "grills" out there, though some restaurants may still grill their steaks in a way that you and I would recognize. However, many restaurants use overhead, infrared broilers that produce incredible temperatures to cook steaks. While you can buy similar equipment, it isn't necessary for a great steak. What you do need is incredibly high heat in direct contact with the meat. This is why you need:
The Pan: A basic, inexpensive cast iron pan is the steaks best friend. Heavy on the metal, able to hold a lot of heat, cast iron pans make the perfect steak. Infrared burners can radiate a lot of heat into a steak, but only by having contact with that intense heat can you cook the steak hot and fast enough to make it perfect. The basic process is to preheat the pan as hot as you can get it. Drop in the steak for two minutes. Flip, add butter and put the pan into a very hot preheated oven for about five more minutes depending on how you want your steak done. This is a smoke filled process that can be done on your side burner and gas grill without flooding the house with smoke.
The Process: This process requires you to use pieces of metal that are heated to incredible temperatures. There will be splattering, smoke and possible fire. Be very careful. What happens here is that the pan sears the surface of the meat and immediately begins melting the fat. This fat fries the meat's surface causing caramelization. This makes the sweet of the meat even sweeter. The butter is going to add extra fat to the process and a rich, buttery flavor to the meat. What you get is a sweet, flavorful, mouth watering steak.
The Experience: Nothing beats an experienced steak cook. If you are not experienced then you need practice. Pay close attention to every steak you cook. Prepare everything you can ahead of time. Learn from your mistakes. Record your thoughts and processes. Soon you too can be a great steak cook and amaze all of your guests.