In a small bowl, mix together the mayo, ketchup & mustard to make the sauce.
Preheat a griddle, cast iron skillet, or a non-stick pan to medium-high heat.
Separate the raw beef into 6 to 8 equal parts approximately 75g per taco & roll the beef down onto your tortillas to create an even thin layer covering the entire surface of the tortillas. Sprinkle the beef with sea salt & cracked black pepper.
Lightly grease your pan or griddle with oil then place the tortillas down onto your cooking surface with the beef facing down & fry for approximately 2 minutes.
Flip over then top the beef with shredded cheese & continue cooking for 1-2 minutes or until the tortillas are crisp and the beef is cooked.
Remove from the heat & add your toppings.
Fold and eat like a taco.
To serve, fold and eat with french fries and ketchup.