Cooking Steps

• Thinly slice the yellow onions, making them as thin as possible for quick cooking and caramelization into the patty.
• Divide the ground beef into four 2-3 ounce portions and lightly form them into balls, avoiding overworking the meat.
• Place a heavy cast-iron skillet or griddle over high heat, preheating for 5-7 minutes until screaming hot, then add a tablespoon of neutral oil or butter.
• Place a beef ball on the hot griddle, immediately pile generous onions on top, then firmly smash it flat to 1/4 inch thick with a sturdy spatula, holding for 10-15 seconds; season with salt and pepper.
• Cook the first side for 2-3 minutes until edges are crispy and juices rise, allowing the embedded onions to sizzle and caramelize.
• Once a deep crust forms, scrape under the patty to keep crispy bits and onions, then flip and immediately add a slice of cheese.
• While the second side cooks, butter the buns and toast them face-down on the griddle until golden brown.
• Cook for another 1-2 minutes until the cheese is melted and the burger reaches desired doneness, ensuring deep caramelization of the onions.
• Remove burgers from the griddle, place on toasted buns, add desired toppings such as ketchup or mustard, and serve immediately.