1. Put the masa flour in a bowl. Slowly add the water, about 1/4 cup at a time. Mix the dough with your hands until it comes together and is pliable, but not overly sticky.
2. Roll the dough into 4-5 balls per cup of corn flour used.
3. Heat a cast iron skillet over medium high heat.
4. Cut two circles out of a clean, thin, plastic shopping bag. Place one of your dough balls between the two sheets on your tortilla press.
5. Remove the raw tortilla carefully from the plastic sheets. Alternatively, you can use a rolling pin to flatten the tortillas.
6. Add a tiny bit of avocado oil to your hot cast iron skillet. Immediately lay the tortilla into the pan.
7. Cook the tortilla for about 30 seconds and then use your fingers or a silicone spatula to flip the tortilla. Cook the tortilla for another minute or so, adding a tad more avocado oil. Do not use metal tongs or a metal spatula to flip the tortillas or they will break.
8. When the tortilla is nice and brown, remove and wrap in a dish towel or cloth napkin.
9. Continue making the tortillas this way until you have made them all. You can keep them wrapped up in the towel for a few hours.
10. If you'd like, tortillas can be frozen and quickly reheated in a hot cast iron skillet with a little avocado oil.