BIG MAC SMASH TACOS

Ingredients:

For the Burger Patties:
1 lb (450 g) ground beef (preferably 80% lean, 20% fat)
Salt and pepper, to taste
For the Special Sauce:
1/2 cup mayonnaise
2 tablespoons ketchup
1 tablespoon yellow mustard
1 tablespoon sweet pickle relish
1 teaspoon white vinegar
1/2 teaspoon onion powder
1/2 teaspoon garlic powder
1/2 teaspoon paprika
For the Tacos:
6 small flour tortillas
1 cup shredded lettuce
1/2 cup finely chopped onions
1 cup shredded cheddar cheese
Dill pickle slices
Sesame seeds (optional, for garnish)