The Perfect Cheeseburger (Inspired by The Menu)

In a bowl, combine the ground beef and onion dip mix, mix until thoroughly incorporated. Split the meat in half and form into 2 balls. Heat olive oil in a large cast iron skillet over medium-high heat. Leaving enough room for the onions on the side, add the burger patties into the skillet and use a sandwich press or spatula to smash the patties down. While the burgers cook, add the sliced onions to the side of skillet, and sauté, stirring frequently, until softened and slightly caramelized. Allow burgers to cook for about 5 minutes, then flip. The side that cooked should be darkened and have nice color. Add 1 slice of cheddar and 1 slice of American cheese on top of each patty. Allow the cheese to melt and the other side of the burger to cook for about 5 minutes, or until your desired doneness. Remove burgers and onions and set aside. Heat butter in a separate pan over medium-high heat. Place burger buns cut side down and allow to toast until nice and golden. Assemble the burgers: on the bottom toasted buns, spread mustard and ketchup. Top that with the cheeseburger patties, then layer on pickle coins, tomato slices, and a handful of sliced lettuce. Close the top toasted bun atop, and enjoy!