Make the Big Mac sauce: There are a lot of different ways to make Big Mac-style sauce, and everyone seems to have their own version, but this one is simple, creamy, tangy, and really brings the whole recipe together. In a small bowl, mix 1/2 cup mayonnaise, 2 tablespoons finely chopped dill pickles or pickle relish, 1 tablespoon yellow mustard, 1 tablespoon ketchup, 1 teaspoon white vinegar, 1/2 teaspoon paprika, 1/2 teaspoon garlic powder, and 1/2 teaspoon onion powder or finely crushed onion flakes until smooth and creamy. Place it in the fridge while you make the tacos so the flavors can come together.
Prep the tortillas and beef: Before you start cooking, have everything ready to go since these tacos cook fast. Shred your lettuce, get your cheese and pickles set aside, then take your small flour tortillas and press a thin, even layer of ground beef onto one side of each one. Season the beef with a little salt and black pepper, pressing it down well so it sticks to the tortilla.
Cook the tacos beef-side down: Place each tortilla beef-side down onto a hot griddle or skillet over medium to medium-high heat. Let them cook for a few minutes until the beef is nicely browned and cooked through.
Flip and add the cheese: Flip the tacos so the tortilla side is now down, then place a slice of American cheese or sliced cheddar over the hot beef right away so it can start melting.
Finish, top, and serve: Cook for another minute or so until the tortillas are lightly golden and a little crispy on the bottom and the cheese has melted over the beef. Remove the tacos from the griddle, then top with shredded lettuce, pickles, and a spoonful or drizzle of Big Mac sauce. Serve them right away while they’re still hot, crisp, juicy, and loaded with that creamy burger-style flavor.