Heat a skillet or cast iron pan over high heat.
Divide the ground beef into 9 equal portions and form them into round balls. Place each ball onto each tortilla. Push the meat down until flat and the same or diameter as the tortillas. Season the meat generously with salt.
Place the burger patties onto the hot surface. Using a spatula, press down firmly on each patty to smash it flat. Cook for about 2-3 minutes, until the bottom is browned and crispy. Flip the tortilla and cook for another minute on the tortilla side, until crispy on the edges.
In a small bowl, whisk together the secret sauce of mayo, ketchup and relish until combined.
Remove the smash burger on the tortillas to a plate and top with shredded lettuce, diced tomato and drizzle with alot of secret sauce. Enjoy!