In a medium bowl, combine the ground pork, shredded cabbage, soy sauce, sesame oil, ginger, garlic, optional green onions, salt, and black pepper. Mix gently until just combined.
Place one wonton wrapper on a clean work surface. Add 1 heaping teaspoon of pork filling to the center.
Lightly wet the edges of the wrapper with water with your index finger. Fold it diagonally into a triangle and press firmly to seal. Repeat with the remaining wrappers and filling.
Heat a thin layer of neutral oil in a large nonstick skillet over medium heat. Arrange potstickers in a single layer, flat-side down.
Cook for 2 to 3 minutes, until the bottoms are golden brown.
Carefully add ½ cup water to the skillet and immediately cover with a lid. Steam for 5 to 6 minutes, until the pork is cooked through and reaches 160°F.
Remove the lid and cook for 1 to 2 minutes longer, until the remaining water evaporates and the bottoms crisp again.
Repeat with the remaining potstickers, using fresh oil and ½ cup water for each batch.
For the dipping sauce, stir together the soy sauce, rice vinegar, sesame oil, and chili crisp or red pepper flakes, if using.
Garnish with sesame seeds and green onions. Serve the potstickers warm with dipping sauce.