Add the cassava flour, extra virgin olive oil, and salt to a bowl. Add one cup of water, mix with a wooden spoon or spatula and start adding the rest of the water. When you cannot use the spatula anymore, start mixing with your hands.
This is the secret to a very elastic dough, so don’t skip this step. Once the dough becomes homogeneous, knead it for about five minutes until the dough becomes very elastic, and you start to hear and feel pockets of air inside it. You have to stop before it becomes sticky.
Shape it into a ball and portion it into eight equal parts. While you are working on each tortilla, cover the rest, so they don't dry out.
Roll them all out with the rolling pin or use a tortillas press. Place them in between squares of parchment paper. After rolling them out, you will start to cook them.
Heat a dry cast-iron skillet on the stove or on the grill. It has to be hot before you add the first tortilla. Cook for about two or three minutes on each side; they will start forming brown blisters and air pockets.
Once cooked, put them on a towel and partially cover. If you cover them entirely, steam will be formed. You can eat these straight away, or you can make them in advance and quickly warm them up before serving (you can also use them cold or freeze).