Oklahoma Onion Burger

Instructions

1. Using a mandoline slicer, set to its thinnest setting, slice the onions into paper-thin pieces. Set aside.
2. Divide the ground beef into four equal portions and gently shape them each into a ball. Try your best not to overhandle the meat—a common burger mistake.
3. Preheat a flat-top grill plate (or electric griddle) over medium-high heat. When the surface is hot, melt the butter onto the surface, and then place one ball of beef onto the griddle. Working quickly, season the beef generously with salt and pepper and then top with a heaping mound of the thinly sliced onions.
4. Using a cast-iron grill press or a large metal spatula, smash the burgers flat, pressing the onions into the meat as you work. Keep smashing until the burgers are about 1/4-inch thick. Repeat with the remaining three burger balls and onions.
5. Let the first side of the burger cook until a nice crust forms and the edges of the meat have started to crisp. Carefully flip the burger so the onions are now under the patty. Press again and then let cook until the onions have caramelized, and the burger is cooked to your preferred doneness.
6. Transfer the finished burgers to buns (we went for a double patty because…why not, but one patty will do just fine?) and top with your choice of burger toppings.