Next is a two-step process; Five Guys starts the burgers and the buns at the same time, but on different grills. Obviously these are at two different temperatures. The buns are not coated with butter or mayonnaise, but they do have more egg flavor than the average sesame seed bun. With two eyes going on your stove, set one to about a little less than medium (3.5 to 5 if your stove uses a 10-point scale) and one to about medium-high (about 6.5 on my stove). The cooler one is for the buns, the hotter one is for the burgers. You don't want water dancing off the pan like it's MC Hammer, just hot enough to give it a solid sear.
If you really insist on just toasting the buns in a toaster, you want to aim for a lightly toasted bun and use the bagel setting so you don't toast the top and bottom of the bun. You can do that, but just live with the shame that you're cheating.
Place two of the burgers down on the hot pan/flat top. Five Guys doesn't touch them for about 30 seconds. After that, dig in — they're usually pretty stuck to the grill — and flip them. Then flatten the daylights out of 'em. Five Guys uses a heavy press, but like always you can get it done with a spatula providing you press out toward the edges from the middle to get that sucker flat. If you don't have a heavy press, you won't get your burgers quite as wide as Five Guys does. That's not necessarily a bad thing, but don't freak out if they seem a bit on the smaller side.
There's a school of thought that says pressing down a burger is akin to leaving kittens floating in a box on a river. But if you do it the right way, you'll actually make the burger meatier and more flavorful. Five Guys flattens them but in a very specific way: the wrong way. The trick is to smash immediately once you put meat on the hot surface, but Five Guys doesn't do that. By waiting until the flip, some of the juiciness escapes from the burger. But you're here for a Five Guys burger, so do it wrong.