Preheat your grill to a medium, direct heat. Place a large griddle or cast iron pan in the grill. We used our comal.
Make the special secret sauce: combine the mayo, ketchup, relish, garlic powder and Salt Pepper + Three Chiles. Check for seasoning and add salt, if needed.
Divide the beef into four equal parts and roll them into meatballs. Season with salt and pepper.
Lightly oil the pan and place the burgers on the pan. Once juices start to pool at the bottom of the burger use a smash burger press or large metal spatula to smash the burger until it is SUPER THIN! Add the onions.
Once you see juices pooling on the meat flip the burger. Add the cheese and place a bottom bun on two of the four patties. As soon as the cheese is melted pull them off.
Flip the bottoms over and add the other burger to make two doubles. Top with three pickles, shredded iceberg, and a big spoonful of the secret sauce.