Chop the napa cabbage into small pieces and add 1 tsp of salt and mix. Let sit for 15min, massage with hands to draw moisture out of the cabbage leaves. Drain the excess liquid out.
Dry the extra firm tofu, and crumble it up with your fingers in a large bowl. Add in the fresh or rehydrated chopped shiitake mushrooms
Mix all the ingredients (except for the dumpling wrappers) in a large bowl. Mix thoroughly by hand for 10-12 minutes until the mixture forms a paste.
Make a test wonton. Wet the edge of half of the wrapper. Place a generous amount of filling in. Fold the wonton up. Cook the dumpling in a pot of bowling water, or chicken stock. When the wonton floats it is ready. Adjust the seasoning of the mixture to suit your tastes, and continue wrapping.
If you aren't eating the wontons right away, I recommend that you place the uncooked wontons on a baking sheet lined with parchment paper. Pop the baking tray in the freezer. After 1-2 hours, you can transfer the wontons to a ziploc bag and store in the freezer. Now the wontons won't stick together, and you can enjoy them whenever.