Everyone above is correct. HIGH HEAT. However I must add to the discussion. Meat selection is more important than technique, because it has a more dramatic effect on the end result. Each dish requires a different cut of meat. You must think, no one is going to grind filet mignon up to use for hamburger! Sirloin is meant to be cooked as a whole steak, think about other steak dishes that are thinly sliced, pan cooked, juicy and delicious, one mainly comes to mind and it is not Asian- FAJITAS! skirt steak is all I know people to use for fajitas. If you wish to cook a nice whole steak get a New York Strip Steak that is USDA Choice or better, only because you need the marbeling (intramuscular fat) for flavor. High heat, salt and pepper the crap out of it at room temperature before cooking (the salt and pepper intensify the flavor while also assisting in denaturing the proteins a bit, helping to make a more tender steak). Little oil in an incredibly hot pan. Brown on one side (NOT Carmelized, which is the browning of sugars, the browning of protein is called the Maillard Reaction)then turn steak to other side, cook till almost deep brown and put in a 400 degree oven until cooked to your liking.
Other notes:
Mounting with butter, before putting the steak in the oven. The French Emperor Chef, Escoffier called it "monte au beurre", top it with some unmelted butter.
*Remember, steak does not stop cooking once you pull it out of the
oven.
It is called carry over cooking, the same goes for Turkey, roast beef, even hamburgers. If you want a meduim steak, you have to pull it out when it is medium rare. The internal temperature will keep cooking the meat so if what you pulled out of the oven was medium, by the time you cut into it, you have a dry, flavorless well done steak. Thanksgiving turkeys have that pop up timer on it that is set to go off when the internal temprature is 155 F. however it carries up to 185 and the turkey is ruined!
***FAT IS GOOD***
I personally hate filet mignon because although very tender, there is no fat on it and therefore no FLAVOR. why do you think everyone bacon wraps them or rolls it something extremely flavorful? If you want a tasty peice of meat, get one with a high fat content.
**RESTING**
All meat must rest. When you cook meat, roasts, or ground burgers, the juices are moving around and they generally always move to the center. When you are so hungry and cannot wait any more, you cut into the meat juice and blood come pouring out, looking like an 80's slasher film, and you go "oh yeah, thats a juicy steak!" However the experience is lacking flavor and the juiciness you thought you had, leaving you feeling abandoned and lonely. LOL. When you let your steak rest for 8-12 minutes you are giving it time for the juices to re-disperse and settle into every litte knook and cranny of that steak, hence making your dinner an exceptional one.
Protein cookery is VERY difficult and a lot of people take a perfectly cooked peice of meat for granted. Sorry for the runons and grammatical errors.