Begin by using your hands to crumble a drained block of extra-firm tofu. As you crumble, excess water should be leaving the tofu.
Finely mince shiitake mushrooms. (Use a food processor for faster mincing).
Cut the napa cabbage in half, keeping the root intact. Then, thinly slice the cabbage horizontally.
Heat a pan over medium-high heat. Add neutral oil.
Sauté the minced ginger and garlic first, then add the minced shiitakes. Stir until the mushrooms begin to soften.
Next, mix in the crumbled tofu.
Turn the heat up if necessary and stir until all of the moisture is released from the tofu and it begins to brown. About 2-4 minutes.
Stir in the soy sauce and sambal oelek, then mix in the chopped napa cabbage. Sauté until it has shrunk in size by about half.
Lower the heat and mix in the sugar and MSG (optional).
Turn off the heat and let it cool.
To form the dumplings, place one dumpling wrapper in your non-dominant hand.
Scoop about 1 teaspoon or tablespoon or so into the center of the wrapper. Be careful not to overstuff.
Use your fingers and a small bowl of water to lightly wet the outer edges of the wrapper.
Fold the dumpling upwards in a half-moon shape, but do not connect the two sides yet.
Start from one corner and fold and pleat the edge until you make it to the other side. Refer this video on How to Fold Dumplings for more detail. Tip: Pleating the dumpling is optional. You can also just attach the two sides however you like, it will still taste delicious!
Heat 2 tablespoons of oil in a nonstick pan over medium heat.
Place all of the dumplings flat-side down on the pan. Sear until crispy, about 2 minutes.
Add ¼ cup of water to the hot pan and immediately cover with a lid to steam the dumplings for about 3 minutes or until water is evaporated.
Remove from the pan and serve warm with soy sauce or another dipping sauce!