1. Slice the potatoes and put them in a bowl, sprinkle with salt and leave for 5 minutes. When the water becomes dry, discard the water.
2. Add potato starch, pepper, parsley, and Parmesan cheese and mix evenly.
3. Put the potatoes in a pan over medium heat with cooking oil and spread it flat and bake.
4. When the underside is golden, turn it over and reduce the heat to low, apply tomato sauce and sprinkle with mozzarella cheese.
5. Put the tortilla on top and when the underside is golden, turn it over and bake a little more.