There are many ways to prepare twice-cooked pork. Home-made versions will have you simmer sliced pork (usually skin-on pork belly) in a seasoned liquid until tender, before stir-frying the meat with vegetables, while at restaurants, chefs start the dish with char siu (Chinese barbecued pork) or siu yuk (Chinese crisp-skinned roasted pork).
I prefer the restaurant version, especially with siu yuk (char siu is too sweet). Although this way is more expensive - you have to buy the meat from a Chinese roast meat shop - it has the advantage of being quicker to make because you don't have to boil the pork first. I like making twice-cooked pork with plenty of vegetables, using the meat as a flavouring rather than the main focus of the dish.
The amount of jarred chilli sauce you use depends on your heat tolerance, as well as the brand. Check the ingredients list: avoid the ones with soybeans or black beans (which are chilli bean sauces) and use the roughly textured type that contain chopped chillies, garlic, oil, and perhaps soy sauce and sugar. You will need to adjust the amount of soy sauce and sugar (which balances the heat of the chilli) that you add, depending on the chilli sauce you use.
Use green head cabbage, which maintains its crisp texture when stir-fried, not savoy or Chinese cabbage, which have softer leaves that wilt too much in the heat.
Choose a skin-on piece of siu yuk with a nice layer of fat; don’t use the breast, which is too dry.
Briefly rinse the black beans under running water, then drain them. Put them in a small bowl and add 20ml (4tsp) of hot water then leave to soak for about 10 minutes. Drain them, reserving the soaking liquid. Roughly crush the black beans. Mix the soaking liquid with the soy sauce, chilli sauce and sugar.
Put the dried chillies in warm water and leave to soak for about 10 minutes. Take the chillies out of the water, cut off the stem ends and shake out and discard as many seeds as possible. Cut the chillies into 1cm (7/16in) pieces.
Halve the garlic cloves then thinly slice them. Thoroughly rinse the leeks, then cut them on the diagonal into 2cm (⅞in) pieces, and the banana chillies into 5mm (¼in) pieces. Quarter the cabbage and remove the core. Cut the leaves into two-bite pieces. Slice the siu yuk into thin, bite-sized pieces.
Place a wok (or large skillet) over a high flame and when it’s hot, pour in about 10ml (2tsp) of oil. Swirl the wok to coat it with the oil, then add half the cabbage. Spread the cabbage out in the wok so it has contact with the metal, pressing on the leaves so they char slightly. Sprinkle lightly with salt, then stir, and again, spread the cabbage out. Cook until the leaves are slightly charred (about two minutes) then transfer them to a bowl. Repeat with more oil, the remaining cabbage and a little salt.
Place the wok (no need to wash it) over a high flame, add 15ml (1tbsp) of oil and swirl the wok to coat it. Add the leeks and banana chillies and cook, stirring occasionally, until the leeks start to soften, about two minutes.
Add the crushed black beans and the dried chillies into the wok and stir-fry for about 30 seconds. Mix in the siu yuk, cabbage and soaking liquid/soy sauce/chilli sauce mixture. Stir well so the seasonings are evenly distributed, then add about 60ml (¼ cup) of hot water. Stir the ingredients then push them to the centre of the wok, turn the heat to medium and cover with the lid. Let the ingredients simmer for about two minutes, stirring occasionally, or until the cabbage is crisp-tender.
Remove the lid and taste the mixture. Correct the seasonings, adding more chilli sauce if you like, and/or more sugar, soy sauce and salt.
Scoop the ingredients into a dish and serve with steamed white rice.