Make the Burger Sauce: In a small bowl, combine the mayonnaise, ketchup, American mustard, pickle brine, garlic powder, and smoked paprika. Stir everything together until it's smooth and evenly mixed. Set it aside.

Prepare the Toppings: Finely shred your iceberg lettuce, finely dice the white onion, and thinly slice the gherkins. Having everything prepped and within arm's reach is key.

Portion the Mince: Divide the 500g of beef mince into 8 equal portions (about 62g each). Gently roll each portion into a loose ball. Don't pack them too tightly. Season them generously with salt and pepper.

Heat Your Pan: Place a large, heavy-bottomed frying pan (cast iron is excellent for this) over a medium-high heat. Add the vegetable oil. You want the pan to be very hot before you start – the oil should shimmer slightly.

Smash the Burger: Working in batches of one or two to avoid overcrowding, place a mince ball onto the hot pan. Immediately place a flour tortilla on top of the mince ball.

The All-Important Smash: Using a large, sturdy metal spatula or the flat bottom of a saucepan, press down firmly and evenly on the tortilla. Smash the mince until it is very thin and spreads out to almost the edge of the tortilla. What works best for me is holding the pressure for about 10 seconds to ensure a good sear.

Cook and Flip: Let it cook for 2-3 minutes. You'll see the edges of the beef turn a deep, dark brown and get crispy. Using your spatula, carefully scrape under the beef and flip the entire thing over (tortilla and all) so the tortilla is now on the bottom.

Melt the Cheese: Immediately place a slice of cheese on top of the crispy beef. Cook for another 60-90 seconds, just long enough for the cheese to become perfectly melted and for the tortilla to get lightly toasted and warmed through.

Assemble and Serve: Remove the smash burger taco from the pan and place it on a plate. Drizzle generously with your prepared burger sauce, then top with the shredded lettuce, diced onion, and sliced gherkins. Fold it over like a taco and eat immediately while it's hot and crispy. Repeat with the remaining mince and tortillas.