I've made burgers this way two times now and they are really yummy. I'd thought I'd pass the recipe along.
I mixed in Seasoning Salt, Chili Powder, and Chopped Onion with the Ground Beef and then formed them into patties. I made the patties really big but flat. I also poked a whole in the middle of each burger (this helped them cook all the way through evenly). I heated the grill up to high, then turned down to medium. Cook for 4 minutes on each side, flip them again and top with cheese. Let the cheese melt and the buns toast at the same time. These were really good, I promise!