Mix all filling ingredients together in a large bowl.
Fill gyoza wrappers with approx 1.5 teaspoons filling (don't overfill) brush water on the edges, press firmly in dumpling press if you have one, or just fold over and crimp with your fingers.
To cook/eat now
Heat a small amount of oil on medium heat and add potstickers and cook till bottoms are golden.
Add half a cup of water - cover and let them steam for simmer approximately 6-8 minutes.
Serve immediately with dipping sauce
Dipping sauce
Whisk sauce ingredients in a small bowl - add the chopped green onions when ready to serve.
To freeze
Spread potstickers on a baking sheet until firm, then store in a ziploc bag.
To serve from frozen
Don't thaw, just cook as above, increasing the steam time to 8-10 minutes.