Season ground beef with salt and pepper. Form four round patties and set aside on a plate.
In a large bowl, whisk together all of the sauce ingredients: mayonnaise, ketchup, mustard, pickles, white vinegar.
Take one shaped burger patty and smash it in an even layer onto one mini tortilla, bringing the meat out to the sides. It's okay if the meat goes a little past the edges of the tortilla, as it will shrink a bit when cooking. Repeat with remaining three patties and tortillas.
Heat olive oil on a large skillet over medium-high heat. Place one burger patty and tortilla, meat side down, and cook for about 2-3 minutes, until the meat is mostly cooked.
Flip over so the tortilla side is down, top with slice of cheese, and cook for an additional 2-3 minutes, until the cheese has melted and meat is fully cooked. Repeat with remaining three burgers and tortillas.
Top each with lettuce, pickles, and drizzly with sauce. Serve immediately, either folded up like a taco or serve open faced.
Notes
Makes 4-5 Big Mac smash tacosTip: make sure you press the beef out in an even layer so that it at least touches the edges of the tortilla rounds. The meat will seize up and shrink a bit as it cooks, so make sure you press it into a thin even layer. This will also make it easier to fold it up like a taco when it's cooked.Ingredient notes:
Use mini flour tortillas for the best result.
I use ground beef that is an 80/20 mix, which gives you big flavors still but less fat.
You can use your favorite sliced cheese. I use dairy-free slices and it's just as delicious!