There are very good reasons for leaving meat to rest. In the cooking process, the proteins in meat set, meaning that the juices all go to the middle and the outer part effectively dries out. When you rest the meat it cools just enough for those juices to be redistributed and the outside becomes moist and tender again. For a 200g piece of steak, rest it for six to 10 minutes. I leave it uncovered in a warm part of the kitchen, perhaps over a stovetop. Larger pieces, such as roasts, I rest for up to 30 minutes covered with tinfoil.