Measure and roll the beef into 3.5 to 4oz balls. Set aside until you are ready to cook. Optional - you can smash them now with the back of a flat bottom bowl or burger smasher, just make sure to and layer between parchment so they don't stick to each other. This will help speed things along at the grill or stove top.
Using a cast iron pan, griddle or other flat bottom pan, heat to at least 350F (stove top or grill will work here, you just need that flat bottom so the fat and juices collect in the pan while the burger cooks to promote browning).
Drop the ball of beef onto the pan. Use a large flat metal spatula without holes (you can cover a regular metal spatula with aluminum foil to get the same effect) or a burger press to press down on the burger to at least 1/4 inch thick. The thinner the better! (Tip: If you are finding the meat is sticking too much to your burger press, lightly grease the press before smashing.)
Sprinkle with salt and pepper on one side. Allow to cook undisturbed for 2-2.5 minutes or until the edges start to get a deep brown caramelized look. Meanwhile toast your buns if you like.
Flip the burger, it should be golden brown all over on one side. Season the other side now with salt & pepper and allow to cook for another 2 minutes till golden brown on the bottom or until the burger reaches your desired level of done-ness.
Immediately transfer to a bun, top with a slice of cheese, (another patty if you want a double cheese burger!) add the top half of bun and wrap the whole thing in aluminum foil while it is still warm. Allow to rest at least 5 minutes for the juices in the meat to rest and the cheese to melt before serving.
Add toppings and sauces of your choice. Enjoy your perfectly juicy golden brown delicious smash burger! :)