When I make gyoza [mother in law is Japanese and taught me] I use my food processor and process cabbage carrots onions fresh ginger, garlic and shitake mushrooms. I then mix this into the [raw] meat. Use this raw mixture and make the dumplings and prepare as above.

To make in advance, pan cook, until brown on one side and then remove and cool. freeze flat and separate until hard and then place in a freezer safe container or bag. you don’t need to thaw them all the way. heat in a preheated pan smeared or sprayed with oil for several minutes, then pour 1/2 cup of water in and put the lid on the pan. when you can no longer see steam coming out of the pan, remove lid and check for sticking and give the pan a little shake. Turn out onto a platter and serve with the above sauce for dipping.