Peel and grate the potatoes with a medium grater (or coarse one).
Squeeze grated potato in a hand or in a towel or cheesecloth to remove as much moisture.
Let them drain for 30 minutes.
In the meantime peel and small dice the onion.
Preheat the fat to 180°C. The fat layer should be 2 cm (0,8 inches) thick.
In a large bowl mix drained potatoes, eggs, salt, black pepper, potato starch. Mix well. The mixture should have a thick consistency. If there is a liquid you should remove it.
Add a large spoonful of the mixture to the fat spreading it slightly. Fry for about 2-3 minutes on each side, until the pancakes are golden brown.
Before serving place the potato pancakes on a paper towel, to absorb the excess oil!
Serve warm with apple sauce or herb Quark on the side.