Form ground beef into 3 large patties. Season each patty liberally with salt and pepper on both sides.
Preheat a cast iron skillet over medium high heat on the stove.
Place buns, cut side down on the skillet and toast them until golden brown. Remove buns from skillet and set aside.
Add a tablespoon of lard to the hot skillet.
Cook each beef patty for 3 minutes on the first side. Do not turn, or move the patties around in the skillet. Allow them to cook so that they get a good char/sear on the bottom.
Flip patties over. Top each patty with 2 slices of American cheese and cook them for another 3-4 minutes until cooked through and you have a nice char on the bottom and the cheese is soft and melty.
While burgers are cooking, prepare the buns.
Place a couple tablespoons of the special sauce on each bun, both the bottom and top bun.
Top the bottom bun with special sauce, slices of pickle, diced onion and then shredded lettuce.
Add special sauce and shredded lettuce to the top bun.
Place a cooked beef patty on the bottom bun and top with the prepared top bun.
Serve immediately.