Your steak has been cooking for about four minutes now and if you want it very rare it's time to take it off the heat. If you want it more than very rare you need to transfer it to the preheated grill (or oven). You want your grill (or oven) above 400 degrees F. (205 degrees C.).
Very importantly before you close down the lid you want to drop a pat of butter on the top of the steak right in the middle. This butter will melt almost instantly and pour down over the steak giving it an extra rich, almost nutty flavor. Basically this butter will turn to a rich caramel.
If you want to get a precise temperature reading on this steak you can put in an oven safe thermometer or polder style thermometer (the kind with the remote unit so you can read the temperature without opening the lid).