01 -
Combine mayonnaise, ketchup, mustard, relish, and hot sauce in a small bowl. Set aside.
02 -
Heat a griddle over medium-high heat.
03 -
Divide ground round into 4 loose portions and place them in mounds on the hot griddle. Season evenly with salt and pepper. Cook for 2 minutes.
04 -
Place a tortilla on top of each beef portion and press down to flatten the beef into the shape and size of the tortilla.
05 -
Cook until the tortilla is golden-brown, 2 to 3 more minutes. Flip each patty over and top with American cheese.
06 -
When the cheese has melted and the tortilla has browned lightly, top each taco with shredded lettuce, diced onion, and drizzle with the prepared sauce. Remove from griddle and fold in half to serve.