In a large bowl, place the cassava flour, tapioca starch, baking powder, and salt. Whisk to combine well.

Add the shortening or coconut oil, and mix until evenly distributed through the dry ingredients. Use the back of the mixing spoon to press in the shortening.

Add the warm water and mix, then knead until the dough comes together. It should come together well, but may crumble into moist shards.

Press the dough together, and then cover the mixing bowl. Allow the dough to sit for about 30 minutes. It will absorb moisture as it rests.

Divide the dough into 8 equal portions, each about 65 grams. Work with one piece of dough at a time, keeping the rest of the dough covered.

Place a large, heavy-bottom (ideally, cast iron) skillet over medium-high heat. If your skillet isn’t cast iron or nonstick, grease very lightly to prevent the dough from sticking.

Open the tortilla press and drape the prepared plastic over both halves of the open press. Shape the first piece of dough into a round, press it into a disk, and place it in the center of the plastic-lined bottom of the press.

Close the tortilla press, enclosing the dough on both halves of the plastic, and press the press down using the lever to flatten the dough.

Remove the dough from the press, still in the plastic, and using your rolling pin to roll further into a thinner round, about 6.5-inches in diameter.

Shape the first piece of dough into a round, press it into a disk, and place it in the center of one half of the prepared plastic.

Cover the dough with the other half of the plastic, encasing the disk of dough fully in the plastic.

Use a rolling pin to roll the dough into a thin round about 6.5-inches in diameter.

If you’re using a 6-inch round cutter, press it onto the round of dough to create a clean 6-inch disk. Carefully remove the excess dough from the edges, taking care not to disturb the clean edges.

Press down on the top of the tortilla with a spatula to help the second side cook evenly. Cook the second side until set, about 20 seconds.

Remove the tortilla from the skillet before it becomes stiff.

Repeat with the remaining pieces of dough. Stack the prepared tortillas one on top of the other, and cover with a tea towel to keep them warm.

Once the tortillas are fully cool, you can wrap them tightly in plastic wrap or place the stack in a quart-sized zip-top plastic bag.

Store in the refrigerator for up to 5 days. Refresh in the microwave for 10 seconds, or sprinkle lightly with water and refresh in a hot, dry skillet until warm and pliable.