Instructions

• Thinly slice the yellow onions and divide the ground beef into four 4-ounce balls. Season both sides of the cheese slices with a small amount of salt and pepper.
• Heat a heavy-bottomed cast-iron skillet or griddle over high heat until it's screaming hot and lightly smoking, then add about a tablespoon of high-smoke-point oil.
• Place a beef ball on the hot griddle, immediately pile a generous amount of thinly sliced onions on top, and firmly smash the beef and onions down to a thin patty (about ¼-inch thick), ensuring onions are pressed into the meat. Season generously with salt and black pepper.
• Cook the patty undisturbed for 2-3 minutes until crispy, lacy edges form and the onions are deeply caramelized.
• Carefully scrape under the patty with a spatula to get all crispy bits, then flip it and immediately place a slice of cheese on top of the cooked side.
• While the second side cooks, lightly butter your burger buns and toast them on the griddle until golden brown (30-60 seconds).
• Cook the second side for another 1-2 minutes, or until the cheese is beautifully melted and the patty is cooked through.
• Transfer the cheeseburger patty to the toasted bottom bun, add desired toppings (pickles recommended!), top with the other bun half, and serve immediately.