Chop up the nappa cabbage, shitake mushrooms (Soak for 30 minutes with warm/hot water), and ginger together. This could be chopped in a food processor.
** Take out dumpling wrappers from fridge/freezer at this time.
Combined the chopped ingredients (nappa cabbage,shitake mushrooms,and ginger) with the ground pork along with salt, pepper, garlic, soy sauce, sesame oil, garlic powder, and egg.
Mix the ingredients together. ( you can use your hand or spatula)
This is an optional step, but I usually taste test the filling first, by filling a dumpling and cooking it.
Start setting up your assembly line, you will need a plate, spoon, bowl of water, dumpling filling, and dumpling wrappers all in front of you.
Take your dumpling wrapper, add a small spoonful of your mixture in, dab one finger into the bowl of water and wet half of the wrapper. Fold both sides together and pinch throughout the sides of the wrapper. Make sure there are no air bubbles and no filling out. Then repeat.
You can freeze your dumplings by placing them into the freezer, once frozen you can put them into a zip lock bag.
To cook the dumplings: add them into a pot of boiling water. Cook for 10 minutes (the dumplings should be floating at this point) and enjoy!