Combine ground pork, chopped cabbage, green onions, minced garlic, ginger, rice vinegar, oyster sauce, cornstarch, and black pepper in a large bowl. Mix thoroughly until well combined.
Place 1 teaspoon of filling in the center of each potsticker wrapper. Wet the edges with water and pleat the edges to seal completely, creating a half-moon shape.
Heat oil in a large non-stick pan over medium-high heat. Dust the pan lightly with cornstarch to prevent sticking.
Add potstickers to the pan, crimped side up, ensuring they don't touch each other. Fry until bottoms are golden brown, about 3-4 minutes.
Carefully add chicken broth to the pan, cover immediately, and cook until liquid is absorbed and wrappers are tender, 2-4 minutes.
Remove lid and let any remaining liquid evaporate. Serve immediately while crispy.