Make the Sauce: In a small bowl, mix together the mayonnaise, sweet relish, yellow mustard, paprika, onion powder, garlic powder, and salt. Set aside in the fridge until ready to use.

Caramelize the onions: In a pan, medium heat, add some oil and saute the minced onions until caramelized. 

Prep the rest of the toppings: cut the lettuce into strips, cut the tomatoes, and set the pickles and the rest of the toppings in bowls. 

Prepare the Beef Patty: Season the ground beef with salt and pepper. Divide the beef into 4 equal portions and flatten the seasoned ground beef patties onto the tortillas. 

Cook the Smash Burger Tacos: Heat a large skillet or griddle over medium-high heat. Place the beef tortillas onto the hot griddle or hot skillet and smash them down using a spatula or a burger press. Cook for 2-3 minutes on each side or until browned and cooked through. During the last minute of cooking, place a slice of cheese on each patty to melt. Cover with a lid to make the cheese melt faster. 

Assemble: Add a generous spoonful of smash taco burger sauce, followed by lettuce, caramelized onion, tomato, and pickles.

 

Wrap and Serve: Fold the tortillas around the burgers like a taco and serve immediately.