Tang yuan (or tong yuen) are eaten by Chinese families for reunion dinners, such as for the mid-Autumn festival, winter solstice and Chinese New Year, because the round balls symbolise harmony and togetherness. The glutinous rice flour balls, which have a sticky, stretchy texture, are cooked in sweet and savoury dishes. Although they are sold in the frozen section of Chinese supermarkets, they're very easy to make.
This savoury version of tang yuan reminds me of home; my mother made them often, not just for reunion dinners.
Chung choi are salted turnip greens. In supermarkets, they are sold in small bundles in plastic bags, but in Hong Kong wet markets, some dry-goods vendors prepare their own and they come in large pieces that need to be cut up. Be sure to rinse the vegetables very thoroughly, to rid them of excess salt.
Put the dried shrimp in a bowl, add 200ml (¾ cup plus 1tbsp) warm water and leave to soak until pliable, about 20 minutes.
While the shrimp are soaking, prepare the other ingredients. Put the glutinous rice flour in a bowl and add the hot water. Stir with a pair of chopsticks to form a thick mass. If the mixture is dry, drizzle in a little more hot water. As soon as the dough is cool enough to handle, knead it until it's smooth and holds together when you squeeze it. It should be a little sticky (but not wet), pliable, but firm enough to hold its shape. If it's crumbly, knead in more hot water.
Take about half of the dough (cover the rest with cling film) and shape it into a log. Cut the log into smaller pieces then roll each one into a ball about 1cm (7/16 in) in diameter. Place the balls on a tray or plate lined with plastic wrap. Don't let them touch each other or they'll stick together. Shape the remaining dough the same way then cover lightly with cling film.
Make the meatballs. Finely chop the chung choi and mince the spring onions.
Put the minced pork into a bowl. Add the soy sauce, rice wine, sugar, salt, white pepper, sesame oil and cornstarch and mix thoroughly. Mix in the chung choi and spring onions.
Shape into meat mixture into balls about 1.5cm (⅔in) in diameter and place them on a plate or tray.
Heat a large pot of lightly salted water and when it's boiling, add the glutinous rice balls (tang yuan/tong yuen), cooking them in batches. They are ready when they float to the surface. Scoop them out of the water with a sieve or slotted spoon and place them in a bowl of cool water.
Cut the Chinese radish into thick matchstick strips, about 3cm (1¼ in) long. Julienne the ginger. Drain the shrimp but reserve the soaking liquid.
Heat the oil in a large pot and add the dried shrimp, shredded ginger and salt. Stir-fry for about 30 seconds then add the chicken broth, the shrimp soaking liquid and 15ml soy sauce and about 500ml (2 cups) of cold water. Bring to the boil and add the pork balls. Reduce the heat and simmer for about two minutes. Add the radish and simmer until tender and translucent. Drain the cooked glutinous rice balls, add them to the pot and simmer to heat through, about two minutes. Taste the broth for seasonings and add more salt, if necessary. Ladle the ingredients into bowls, drizzle with sesame oil and top with fresh coriander and spring onions.