This recipe makes 20 dumplings.
Saute chopped mushrooms in oil for about 5 minutes until cooked. Add cabbage, stir, and cook for just one more minute. Let cool to room temperature.
Mix cooked mushrooms and cabbage mixture with remainingl filling ingredients together in a medium bowl. Cover and set at room temperature for 30 minutes to 1 hour to let the flavors marinade.
Next take your dumpling wrapper and cup it in your hand. Place one teaspoon of filling into the center of the dumpling.
Now to close the dumpling there are many techniques. One that I personally like involves closing the dumpling along the diagonal and pinching those ends. Next bring the remaining two sides together and pinch them to seal. This will produce a dumpling as pictured.
Note that there are plenty of ways to make dumplings and even a simple triangular close will work just as well. Also, if you are finding that your dumpling skins are not sealing when you pinch, you can dab a bit of water on the edges you wish you fuse just prior to pinching and that should do the trick.
These dumplings can be used right away by cooking in a broth or they can be easily frozen for use at a later date (if cooking from freezing, add 3 minutes to the cook time).
To freeze, I recommend placing finished dumplings onto a baking sheet lined with parchment paper and placing into the freezer until solid. Once the dumplings are frozen they can be stored in a ziploc bag for months without diminishing in quality.