Add ground pork, scallions, ginger, light soy sauce, Shaoxing wine, salt, white pepper and 3 tablespoons of chicken stock to a mixing bowl. Swirl constantly to combine until the meat fully absorbs the liquid and becomes a sticky paste.
Wrap the wontons
With your fingertip, wet the edge of a wonton wrapper with a little water. Place some pork filling in the middle. Fold the wrapper into a rectangle. Press to seal the edge. From the folded side, wet one corner then place the other corner on top. Press to seal (see video below).
Heat the broth
In a saucepan, heat the chicken broth to a boiling point. Set aside for later use.
Cook the wontons
While the broth is heated, bring plenty of water in a separate pot/wok to a full boil. Gently put in the wontons. Move them around with a spoon to avoid sticking. You may need to cook them in batches (see note 3).
When the wontons rise from the bottom and float on the surface, continue boiling for a further 1½ minutes or so. Put in bok choy and cook for another 20 seconds.
Assemble the dish
Add salt, ground white pepper and sesame oil to 4 serving bowls, then top up each one with the heated broth.
Fish out the wontons and bok choy and put them to the bowls. Garnish with scallions and chili oil (if using).
Make in advance
You may freeze uncooked wontons right after they’re assembled (Do not leave them on the counter for too long). Lay them in a single layer on a tray lined with parchment paper. Once completely frozen, transfer them to airtight bags or containers.
Cook frozen wontons: Do not defrost. Follow the same method above.
1. Make chicken stock from scratch:
Put a whole chicken in a large pot filled with cold water. Bring it to a boil then skim off any impurity floating on the surface.
Add 2 stalks of scallions and a few slices of ginger. Leave to simmer over low heat for 40-50 minutes. Then take out the chicken, scallions and ginger.
2. This recipe makes about 40 wontons if the wrappers are small (about 9cm/3.5in). If using large ones (about 10.5cm/4.2in), you may make about 30 wontons.3. Cook in batches: If you lay the wontons one beside another in a single layer, the area they cover shouldn’t be bigger than the cookware.