Beat the egg with a splash of water. Get your first wonton wrapper ready. Use your finger to rub just a little of the egg wash on all the edges. Stuff it with about a tablespoon of the potato mixture (depending on how big the wrappers are) and fold it over onto itself. Press the edges firmly to seal. Make 5 little crimps in the edge by folding the seam onto itself and pressing firmly to seal. Repeat until you have done all the wontons or you run out of filling.

Heat a thin coating of oil in a frying pan until you see it glistening and moving around a bit. Add in as many potstickers will fit without crowding the pan. Allow to sit for about 3-5 minutes to really brown the edge. Pour in about a cup of water and flip all the potstickers. Cook another 2 minutes in the water before removing from the pan.