Whisk together mayonnaise, ketchup, hot sauce, and pickle juice in a small bowl and set aside.
Heat a large cast iron skillet or griddle over high heat. Season 1 side of ground beef with half the salt, pepper, and garlic powder. Add beef, seasoned side down, into the hot pan and use spatula to flatten it into a large patty about a 1/2-inch thick. Let the beef cook undisturbed until browned, about 4 minutes.
Flip the beef and let it cook 1 more minute before using the spatula to chop the meat into smaller pieces. Add onion and continue to cook, while chopping the mixture into very small pieces.
Top with cheese and allow to melt, about one minute. Add pickles and then use 1 or 2 spatulas to combine the ingredients. Remove from heat.
Divide meat mixture among tortillas and top with shredded lettuce, crushed chips and a drizzle of reserved sauce.
