01 - Preheat a large cast iron skillet or griddle over medium-high heat until hot.
02 - Divide ground beef into 8 equal portions and roll each into a ball, approximately 2 ounces each.
03 - On a work surface, place one tortilla flat and position one beef ball in the center. Press to flatten the meat into a thin layer, covering most of the tortilla using your hand or a spatula.
04 - Place the tortilla with beef side down onto the hot skillet. Press firmly with a large flat spatula to spread the beef. Season with a pinch of kosher salt and freshly ground black pepper.
05 - Cook for 2 to 3 minutes until beef develops a deep brown crust and crispy edges. Flip so the tortilla is against the skillet; immediately top the beef with half a cheese slice. Allow cheese to melt as tortilla toasts, about 1 minute.
06 - Repeat the process with remaining tortilla and beef portions, adding butter to the skillet for enhanced flavor if desired.
07 - Top each taco with shredded lettuce, sliced red onion, tomato slices, pickles, and a drizzle of burger sauce, ketchup, or mustard as preferred. Fold and serve immediately.