An ordinary domestic grill can never get hot enough to cook steak properly.
I work in pro kitchens, a steak grill has a solid metal plate on the bottom and a very hot gas burner over it. The grill plate slopes down so that the back is nearer the heat and hotter than the front. The grill will be on and running at max heat for around 30 mins before service even starts. The hottest part of the grill will be 400 to 500 deg's !
The steak is seared on both sides at the very high heat at the back of the grill, then the chef moves it forward so the heat decreases to cook it through.
It takes a lot of skill and experience know where to place the meat to get it cooked correctly the way the customer wants it. Secondly and very important the steak a top restaurant buys is the very highest quality, hung for 28 days. There is a VERY limited supply of meat of this quality and none gets to supermarkets. You may be able to get meat of this quality at a small independant butcher who buys his meat 'on the hoof' but be prepared to pay for it. I am talking of around £20 to £35 a kilo!