Fire up your grill for medium-high heat. Place a griddle or a large cast iron pan over the highest heat.
Season the ground beef with the salt and pepper, mix and form into two 4 ounce balls (not patties!).
Place the balls of beef on the griddle and let cook for one minute. Just let them cook, don’t mess with them.
Take your press and flatten out the patties. I like to use the point of the press and work my way around the ball first, doing a little section at a time and then finally I press down on the entire patty to flatten it out. You can also just flatten out the ball all at once. At this point I also like to season the patties some more.
Let the patties cook until you start to notice a little char along the edges. Flip, season again if desired, and continue cooking another minute or so until the other side is charred. The burgers are thin so they will cook very quickly so watch out.
Top patties with cheese and let cook another 30 seconds to melt the cheese.
Remove patties from grill and toast buns if desired.
Slather insides of buns with mayonnaise.
Add patties to bun bottoms. Top with onion rings and BBQ sauce.
Notes
After you make a few smash burgers the process becomes very easy and always delivers great results.