Step 1

Make the special sauce: In a small bowl, stir together the mayonnaise, relish, ketchup, hot sauce and garlic powder until combined. Taste, and season with salt and pepper, as desired.

Step 2

Make the tacos: Heat a griddle or large cast-iron, carbon-steel or stainless-steel skillet over medium-high heat until very hot. Meanwhile, divide the meat into six equal portions, about 2 1/2 ounces each, and press each portion onto one side of a tortilla to cover the entire surface. (The patty will shrink away from the edge of the tortilla as it cooks.) Lightly season each patty with salt and pepper.

Step 3

In batches, depending on the size of your griddle or skillet, add the tortillas to the hot skillet meat side down and cook, pressing each regularly with a spatula, until a nice brown crust forms, about 3 minutes. Flip the tortillas over, top with a slice of cheese and cook until the tortillas are crisp on the bottom and the cheese has melted, about 1 minute more. Transfer the tortillas to a platter or individual plates and repeat with the remaining tortillas. Top each with pickles, lettuce, onions, the sauce and sesame seeds; serve hot.