Whip the egg whites and cornstarch together in a small bowl.;
For the filling:
In a large bowl, mix all filling ingredients together.
Lay 12 wrappers on flat surface. Place approximately 1 tablespoon of filling in center of each. Wet edges with egg wash, bring all sides to the center and pinch together.
Steam potstickers in a steaming pan for 6 to 8 minutes. Do not stack. Handle carefully when ready to remove from the pan.
In a large skillet heat peanut oil and sear potstickers until golden and crisp.
For the ponzu sauce:
Mix all ingredients in a small bowl and serve with potstickers;