Flash boil the Chinese greens or spinach and then run under cold water to stop the cooking process. Squeeze the water out of the vegetables and dice finely and set inside a medium mixing bowl.
In the same bowl you put the chopped Chinese greens put in minced pork, green onion, soy sauce, rice wine, salt, white pepper, ginger, garlic, egg and sesame oil and mix well.
Dip your fingers into the water bowl and place a little water around the edges of one wonton wrapper. Make sure you cover the rest of your wonton wrappers with a damp tea cloth, so they don’t dry out while you are stuffing the wontons
Place a heaping teaspoon of pork mixture in the middle of the wonton. (Do not overfill the wonton or otherwise it will burst open during the cooking process)
Fold the wonton wrapper in half and make sure you press tightly around the edges of where the pork mixture is, so you have a good seal.
Fold the wonton over so it looks like a little flying nun hat and then fold the two ends on top of each other to seal. The finished product should look like a nurse’s cap or maybe even a flying nuns cap depending on your technique.
Place your finished wontons on a baking sheet lightly rice floured/corn starch or waxed paper lined baking sheet to prepare for the soup. Alternatively, wontons can be frozen and used later. (If you decide to freeze some, freeze them flat on a baking sheet and once they are frozen you can transfer them to a plastic baggie. This prevents them from sticking together.)
How to cook your wontons: Bring a large pot of salted water to a boil. Add about 6-10 wontons to your pot. (depends on the size of your pot) Make sure there is enough room for them to move about freely. The wontons will cook for a total of 5 - 8 minutes or until they rise to the top and the filling is cooked through. (VERY IMPORTANT! During the boiling process, add about ½ cup of cool water about every 2-3 minutes so that the water does not boil intensively and break apart your wontons- total of around 1.5 cups. You will add the cool water 3 times. Do NOT let your wontons boil vigorously as they may burst. Your goal is to bring them up to a boil and then add a little of the cool water to bring the temperature down. Then bring it up to a boil a second time and then add a little of cool water. For the third and final time you will add a little cool water and bring it up to a boil. Remove your wontons from the pot with a slotted spoon. Repeat this process with the remaining wontons.
To serve, place somewhere between 5 - 10 dumplings in a large bowl (depends on how hungry you are) and then ladle with 2 ladles of pasta water over the dumplings. Simply add some salt to taste, chopped green onion, white pepper and a little drizzle of sesame oil.