Made my own Oklahoma Burgers (aka "Smash Burgers) last night. Infinitely better than bought. 4 oz of ground chuck rolled into a ball, then pressed flat (about 1/4" thick, about a 5" circle). Liberally season with kosher salt and black pepper. Butter a hot skillet (medium high). Place patties in hot skillet, and immediately press about 1/2 to 3/4 cup of very thinly sliced onions on top, and over sides of patties. Cook three minutes, and carefully flip, cooking two more minutes on second side. When flipped, place bun bottom on the patty and stack top of bun on this. Put lid over the entire skillet. This steams the buns. Remove buns, and place slice of American cheese on each patty, and cover for 30 seconds. Remove all, and assemble burgers. Recommended condiments and dressing are mustard and pickles. I opted for mustard only, but I did make mine a double. Nearly hurt myself eating it all, but it was so worth it. The crust developed on the patty from the high heat is one of the signature traits of this burger.