Prepare the Filling
Add the chopped napa cabbage and salt to a bowl. Toss well and let sit for 10 minutes to draw out excess moisture.
Rinse the cabbage thoroughly and squeeze out as much liquid as possible.
In a large mixing bowl, combine the ground chicken, napa cabbage, green onions, garlic, ginger, soy sauce, oyster sauce, sesame oil, chicken bouillon, and white pepper. Mix until fully combined.
Cook a small piece of the filling in a pan to taste test the seasoning. Adjust flavors if needed before assembling the dumplings.
Fold the Dumplings
Lightly wet the edges of a dumpling wrapper with water.
Place a small spoonful of filling in the center of the wrapper.
Fold the wrapper in half. Using the front half only, create 3 pleats toward the center on one side, press to seal, then repeat on the other side. Pinch the top firmly closed.
Keep the dumpling wrappers and finished dumplings covered with a damp towel while folding to prevent drying out.
Cook the Potstickers
Heat a drizzle of oil in a non-stick skillet over medium heat.
Arrange about 10 dumplings in the pan without overcrowding.
Sear for about 2 minutes until the bottoms are golden brown and crispy.
Carefully add enough water to lightly cover the bottom of the pan. Immediately cover with a lid and steam for 5 minutes.
Remove the lid and cook briefly if needed to crisp the bottoms again.
Freeze for Later (Optional)
To freeze uncooked dumplings, place them in a single layer on a parchment-lined tray without touching. Freeze until solid, then transfer to a freezer-safe container or bag.
Serve
Serve hot with dumpling dipping sauce, sliced green onions, and sesame seeds.