In medium bowl, whisk together gluten free flour, tapioca flour, potato starch, baking powder, xanthan gum, and salt.

Using your hands, cut in the shortening. No large pieces of shortening or lard should remain.

Add 1/2 cup cold water. Stir with a wooden spoon. Dough will be dry. Add another 1/4 cup water. Stir. Feel the dough. If it starts to hold together and feels damp, stop adding water. If the dough feels dry, add another two tablespoons water. Repeat until dough is moist but not wet.

Generously flour your countertop. Turn dough out onto counter. Flour your hands lightly with gluten free flour. Gather dough into a ball. Knead the dough until smooth. If the dough is too wet, knead additional flour into it; if the dough feels dry, knead a splash more water into it. You want the dough to be easy to work with. Pull off a little. Roll it between your palms. It should not stick or fall apart - create balls until all the dough is used.

Cover dough with plastic wrap. This prevents a skin from forming.

Heat cast iron skillet over medium heat. While skillet heats, dust the the tortilla press with gluten free flour.  Place the dough ball into the press and close to flatten.  Lift the press and pull out the tortilla. Repeat until all the balls have been pressed.

Increase the heat under the skillet to medium-high if the skillet isn't smoking lightly. Place the tortilla into the skillet. Cook, two to three minutes, until the tortilla is golden brown.  Remove and place hot tortilla onto a plate. Cover with a clean, dry towel.

Serve and enjoy!