The rice cakes in Chinese, Korean and Japanese cuisine are made from pounded glutinous rice, giving them a chewy texture. They're available fresh (not easy to find), dried and chilled. You need the chilled type for this dish.
This dish takes less than 30 minutes to prepare and cook, although you do need to soak the rice cakes in advance. If you like, start in the morning and leave them at room temperature (or in the fridge, if it’s very hot in your kitchen); by the time you get home for lunch or dinner, they will be ready to cook.
Zha choi (also known as zha cai) is Sichuan salted mustard stem. It's a khaki green vegetable covered with a red layer of chilli paste that should be rinsed off before using the vegetable. It's salty and intense.
Put the rice cakes in a bowl, add warm water to cover them by about 3cm (1¼in) and leave to soak for several hours. Separate the rice cakes if they are stuck together, then drain in a colander.
Cut the pork belly into thin strips about 8mm (⅜in) wide. Put the pork pieces in a bowl, add the soy sauce, rice wine, sugar, salt, white pepper, cornstarch, and sesame oil, and combine well. Rinse the zha choi thoroughly then blot with paper towels before cutting it into thin matchsticks. Halve the garlic clove. Cut the spring onions into 2cm (⅞in) lengths.
Place a wok over a high flame and when it’s hot, add the oil. Heat the oil until it shimmers, then add the garlic and ginger. Stir fry for about 15 seconds, then add the pork. Stir-fry until the meat starts to lose its pink colour, then add the rice cakes and zha choi. Cook for about 30 seconds, then add about 120ml (½cup) of water and push all the ingredients to the centre of the wok.
Cover the wok with the lid and turn the flame to low. Cook, stirring often, until the rice cakes are soft (they will still be chewy). Add water as needed, if the mixture gets too dry.
Stir in the spring onions and cook for about 15 seconds, then scoop the ingredients onto a serving plate. Serve with a dish of stir-fried vegetables.