1) Split ground beef into three 6-ounce balls. Then split each of those balls in half to have 6 3-ounce balls. Smash each of those balls into flat patties.
2) Fold your cheese slices into quarters and stack each slice onto a 3-ounce patty. Cover it with another patty and seal it around the edges so the cheese is completely enclosed. Take your time to make sure the burgers are even and sealed well. Season each burger with salt and pepper and make a small indent in the center of each one.
3) To cook the burgers, add a small drizzle of olive oil to a cast iron skillet over medium heat. Add the burgers and cook for 5-6 minutes per side until they are cooked through. At the end of cooking, I recommend adding a drizzle of water and quickly covering the skillet with a lid or big bowl to steam the burgers quickly.
Serve the juicy lucys immediately on toasted buns with condiments.