In a medium bowl, mix together the flour, baking powder, and salt.
Using a party cutter (or your fingers), cut the vegetable shortening into the flour mixture until it is fully incorporated.
Add 1 cup of water to the mixing bowl and stir until no loose flour remains. (If needed, use up at ¼ cup of additional water.)
Knead the mixture for 1-2 minutes, or until a soft dough forms.
Cover the dough loosely with plastic wrap and let it rest for 10 minutes.
Divide the dough into 15 pieces of approximately equal weight. Shape each piece into a tight ball, cover loosely with plastic wrap, and let rest for 10 more minutes.
On a lightly floured work surface, roll each tortilla into a circle about 8” in diameter.
Heat a cast iron skillet on medium-high heat until a drop of water “sizzles” when dropped in the skillet.
Place one tortilla in the skillet and cook for about 35-40 seconds. Flip tortilla and cook for another 35-40 seconds. (Note: The tortilla will bubble slightly and light brown spots will form as the tortilla cooks. This is normal. If the spots are black, then reduce the temperature of the pan.)
Store cooked tortillas in a 200°F oven or tortilla warmer until ready to use. Leftover tortillas can be stored in an air-tight container in the refrigerator for 2-3 days.