The taco is one half the tortilla. It's not crunchy, it's not cold, it's not blond, it'snot cracked or split. It's warmed on a comal 30 seconds per side. It's fried in the fat from the cooking meat, it's doubled.
The meat is diced, never ground. The heat is ripping hot, water droplets skittering on the surface. Otherwise, the meat goes grey and is steamed. 2 minutes per side, then cut into cubes on the board and cooked again 1 minute to finish more edges and surfaces. The cuts are cross-grain.
There is no packet. The taquero seasons the meat with:
Toppings include:
A taco is 3 bites. (Here's where I disagree a little bit. I have never liked tiny tacos. Clearly she's speaking about authenticity.)
A taco is built in the hand and eaten in the same minute.
The hard shell isn't wrong, but it's not a taco either. Again, this is authenticity, but taste is personal.