Get your grill/pan/etc hot.
Salt & pepper the ground beef and then divide into 2/3 lb portions. Flatten into patties, cover with plastic wrap, and flatten with the bottom of a pan.
Break cheese into strips and form two piles. Insert cheese piles into the center of the first patty.
Take the 2nd patty and place it on top. Pinch corners of the two patties together, ensuring there are no holes.
Grill your burgers about 4min on the first side.
Flip burgers. Put the buns face down on the grill. Cook until you reach the correct temp (140F for medium), usually about 2 to 4 minutes.
Enjoy carefully, that molten cheese center is hot!