Cut the potatoes into large quarters and steam over high heat for 15-20 minutes or until you can mash easily with a fork. Drain off any excess liquid that is pooling in your steaming plate/tray and mash while the potatoes are still warm and then let the potatoes sit in the steamer for 10 minutes or longer to 'dry up'.

Fill inner pot with 1 cup of water. Put a collapsible steamer rack inside the inner pot. Cut the potatoes into large quarters and place potatoes on the steamer rack. Close the lid and pressure cook on high for 5 minutes. Wait 5 minutes and then release pressure. Unlock the lid and the potatoes sit in there for 10 minutes to 'dry up'.

Cut the potato into about 1-inch piece. Deep fry the diced potato until cooked but not too brown or it will be hard to mash. Place them in a large mixing bowl and mash with a fork while still warm.

Add the rest of the ingredients for perkedel and mix everything thoroughly. If the potato dough feels a bit too soft, you can add a bit more cornstarch, tablespoon by tablespoon as needed. Shape into patties and put them in the fridge to cool down without covering for 1 hour.

Lightly oil your palms with some cooking oil. Form the mashed potato mixture into balls, then slightly flatten into patties, about ½-inch in thickness. Coat the perkedel in an egg you beaten earlier.

Preheat about 1-inch of cooking oil. When the oil is hot enough, lower the heat to medium. Deep fry until golden brown on one side, about 2-3 minutes and then flip over to the other side and fry until golden brown for another 2-3 minutes. Place on absorbent paper towel and serve warm or room temperature.