To make the potatoes, peel and cut them into 1-inch cubes. Add them to a large pot and cover with water. Bring the water to boiling, then lower the heat to simmer. Cover and simmer the potatoes until they are very tender when pierced with a fork. About 20 minutes.
When the potatoes are done, drain them and run cool water over the colander to stop the cooking process and cool them off.
Transfer the potatoes to a medium bowl and use a potato mixture to mash them.
Mix 2 cups of flour and 1 teaspoon of salt in a separate bowl. Add 2 cups of mashed potatoes and mix with a fork or spoon, then use your hands to form a dough.
Test by forming a ball and flattening it. It should stick together without crumbling or melting into a puddle. If it's crumbly, there is too much flour. knead more and add more potatoes if you have them. If not, add a teaspoon of water at a time, kneading after each addition. If it melts into a puddle, add more flour.
Form 8-12 equal balls, depending on the size of the tortillas. Turn the balls into a lightly floured surface and roll one into a flat disc about ¼ inch thick using a lightly floured rolling pin. You can also use a tortilla press lined with parchment paper or plastic baggies.
Heat a large skillet or cast-iron frying pan to medium-high heat. Once it's hot, add a tortilla. Fry for about 1 minute until the bottom is slightly brown and easily comes off the pan. Flip and fry for another minute.
Place the warm tortilla on a plate and cover it with a tea towel.
Repeat the rolling (or pressing) and frying steps. It's easy to get into a groove where you roll one tortilla while frying the first side of the next.