Roughly chop the shrimp and put them in a food processor along with the pork, scallions, soy sauce, sesame oil, cooking wine and ginger if using. Pulse until well combined but try not to over-puree.
Lay out a few wonton wrappers at a time and have a little dish with water ready beside you. Put a teaspoonful of filling mixture to one side of the wonton - I find easiest putting towards one corner. Put a little water around the edges then fold over the opposite corner from the filling and press together. Join the two sides together, moving from the middle to the edge so you press out any air as you join. Bring the two 'wings' together on one side of the dumpling, using a little water to join. Repeat until you use all the filling.
Season the stock with a little salt and pepper to taste. Slice the garlic and add it, along with the ginger slices and slices of the white part of the scallion. Add a few drops of sesame oil and warm for around 10min or more.
Meanwhile, bring a pot of water to the boil and cook the wontons a couple at a time, making sure there is plenty room in the pot. They are ready after a couple minutes when they rise to the top. Remove with a slotted spoon and add a few to the bottom of each bowl. Repeat until you have enough in each bowl for the number you are serving.
Strain the stock of the pieces of ginger and garlic and pour over the wontons in the bowls. Top with a few slices of the green from the scallion.
Note - if you want to freeze wontons you are not using, do so before cooking. Simply lay them out on a baking sheet lined with parchment then once frozen (after 1hr, approx), transfer to a freezer bag. Stock can also be frozen in a sealed container.