To make the soup base, heat a little oil in a pot and stir fry the chicken wings for about 3 minutes until lightly browned.
Add the water, ginger, and scallions. Simmer over medium heat for about 25 minutes to develop the broth. Season with salt and white pepper.
To prepare the wonton filling, defrost the prawns by running them under cold water for 4–5 minutes.
Cut the prawns into roughly 1/2 inch pieces so the wontons have a chunky texture.
In a bowl, combine the minced pork, chopped prawns, and water chestnuts. Add all the seasoning ingredients and mix well.
To wrap the wontons, place a wonton wrapper in your hand or on a plate. Add a small spoonful of filling to the centre.
Lightly wet the edges of the wrapper with water. Fold the wrapper over the filling and pinch the edges together, then bring the corners together in the centre to seal the wonton. Ensure the wontons are tightly sealed.
Bring a medium pot of water to the boil. Add the wontons and cook for 8–10 minutes until they float to the surface and are fully cooked.
While the wontons cook, add the pak choi to the soup broth and cook for 3–5 minutes until tender.
To serve, place cooked wontons in a bowl, add some pak choi, then ladle the hot soup over the top. Garnish with chopped scallions.