In a small mixing bowl, aggressively whisk together the mayonnaise, ketchup, sweet pickle relish, white vinegar, and granulated sugar until it transforms into a thick, creamy orange-pink secret sauce. Place in the refrigerator to chill.

Heat the cooking oil in a large cast-iron skillet over medium-high heat. Add the ground beef, breaking it apart continuously with a spatula. Season with kosher salt and black pepper. Cook for 6-8 minutes until completely seared, browned, and crumbled.

Reduce the skillet heat to low. Corral the cooked beef into four separate portions in the pan. Lay a square of yellow American cheese over each portion. Allow it to perfectly melt for about 60 seconds, then remove from heat.

In a separate dry skillet over medium heat, lightly toast the flour tortillas for 15 seconds per side until soft and warm, then transfer to serving plates.

Place one portion of the cheesy, browned ground beef onto the center of a toasted tortilla. Generously drizzle the creamy orange-pink secret sauce over the cheese. Top evenly with the crisp finely shredded iceberg lettuce, finely diced white onions, and round crinkle-cut sweet pickle slices. Serve open-faced, then fold or wrap to enjoy.