In a food processor with a blade, mix the flour and vegetable shortening.
Pulse until the shortening is fully incorporated. If not done correctly, the tortillas will have an irregular texture.
Dissolve the salt in the water and pour about 2/3 cup (160 ml) over the dry ingredients and pulse again.
If all the ingredients are not well combined, add the rest of the liquid, a little at a time, and pulse until the dough has a soft and smooth consistency.

Divide the dough into 12 portions and roll each into a ball.
Place them on a plate, cover with plastic wrap, and let rest for at least 30 minutes. This allows the dough to relax and makes it easier to work with the rolling pin.

Heat a thick-bottomed pan over medium heat (6).

Roll out a ball of dough on a floured surface to form a 7-inch (17.5 cm) disk.
Place the tortilla in the hot pan (you should hear a slight sizzling and see the surface puff up immediately).
After 30 to 45 seconds, flip the tortilla and cook until the other side is golden brown.
Do not overcook, or the tortilla will become crispy.
Remove from the pan and keep warm in a cloth placed in a warm place.
Repeat the operation for the remaining tortillas, stacking them on top of each other as you cook them.