1. Place eggs, potato starch, salt, and water in a mixer or food processor and mix well.
2. Heat a small amount of oil in bottom of a frying pan. When oil is very hot, pour in one ladleful of batter. Tilt pan to cover the bottom. Return any extra batter to mixture. As soon as batter bubbles, flip carefully and cook for another few seconds. Repeat until you have used all of the batter, adding a very small amount of oil when necessary to keep the crepes from sticking to the pan.
3. Crepes can be used whole (see some serving ideas here) or can be turned into “Pesach lokshen.” Stack crepes evenly, then roll up as many as you can and slice into narrow strips. Store in refrigerator in an airtight container or zippered plastic bag until ready to use.