Place pork into a mixing bowl; add spinach and green onion; lightly mix together with your hands. (Keep a supply of disposable vinyl gloves for hand-mixing.)
Add soy sauce, sesame oil, salt, ginger and sugar. Mix well together with your hands.
Fill one wrapper with mixture.
(Make one wonton first to gauge how much of the mixture to use and where to place it in the wrappers.)
Lightly moisten outside edge of each wrapper with water.
Enclose the filling by folding the wrapper in half, pinching the ends and center.
Pinch the wrapper towards the center to seal the remaining edges.
Repeat with the remaining wrappers.
Using a large skillet over medium high heat, heat oil until it is hot but not smoking.
Cook the wontons in the hot oil just until the bottoms begin to brown, about 2 minutes.
Add water to the pan, but not over the wontons.
Cover and cook 8 minutes undisturbed.
Remove the cover, and shaking the pan, continue to cook for about 2 minutes or until all the water has been absorbed and the wrappers are a crispy brown.
Remove from the skillet and place bottom side up on a serving plate.
In a small bowl, mix plum sauce, vinegar and sugar. Whisk until sugar has completely dissolved. into a small mixing bowl.
Serve the sauce as a dip.