Prepare the dipping sauce by combining the soy sauce, rice vinegar, water, sesame oil, sugar, and garlic in a glass jar. Seal the jar with a lid, shake well, and set aside to allow flavors to mingle.
Prepare the potsticker filling by boiling the water in a small saucepan over high heat.
Pour the boiling water over the sliced cabbage in a colander to soften.
Place the cabbage in a food processor. Add chicken, green onions, garlic, cornstarch, soy sauce, sesame oil, sea salt, and pepper. Pulse mixer until thoroughly combined. Taste and re-season if needed.
Spread the potsticker wraps out, and scoop a small teaspoonful of filling onto the center of each wrap.
Wet the top of each potsticker wrap with a baster brush dipped in water.
Fold the potstickers in half to make a moon shape. Pinch shut with 3 to 4 pleats along the side. Really make sure they are sealed, so the filling doesn't fall out.
Cook the potstickers by heating the vegetable oil in a large skillet. Once hot, add potstickers, cooking in batches if needed, and cook until the bottoms are golden brown.
Add ½ cup of water and cover with a lid. Steam for 4 minutes.