In a large mixing bowl, combine ground chicken, chopped Napa cabbage, chopped green onions, minced ginger, and minced garlic. Add soy sauce, sesame oil, salt, and black pepper. Mix thoroughly until well combined.

On a clean surface, lay out a dumpling wrapper. Place 1 tablespoon of filling in the center. Moisten edges with water, fold the wrapper in half, and pinch edges tightly to seal. Repeat until all filling and wrappers are used.

In a large skillet, pour in vegetable oil and heat over medium-high heat. Allow the oil to shimmer, then add dumplings in a single layer. Cook for 2-3 minutes until bottoms are golden brown and crispy.

Carefully add water to the skillet and cover with a lid to steam for about 5-7 minutes until water evaporates and dumplings are firm.

Remove the lid and let any remaining moisture evaporate. Transfer dumplings to a serving platter and serve warm with soy sauce or your favorite dipping sauce.