Take my advice and you can't go wrong – simple
Use a large thick-bottomed pan and the real secret is to make sure it’s very hot. Steaks aren’t usually very thick, so if the pan loses heat you won’t get that nice caramelisation you’re looking for when the natural sugars in the meat are released. With a big, hot pan, the meat will caramelise more easily (and a Knorr Cube will make it even easier).
Two or two and half minutes each side should give you that perfect medium rare steak. A little tip is, when you start to see the blood pierce the steak, that's medium to medium rare. Then once cooked, if you have time, allow the meat to rest so that the juices settle and the blood pushes out.