This Shanghainese dish is made with thick, bouncy noodles like fresh Japanese udon, which are given a dark caramel tint by soy sauce and freshened up with barely cooked greens. Pork slivers make a delicious addition, but vegetarians may omit them and still enjoy the dish. In Shanghai, the greens will be the tenderest little sprouts of green bok choy, known as "chicken feather greens"; at home I often use baby spinach because the leaves need to be tender enough to wilt quickly in the heat of the wok. According to some accounts, the recipe was developed by Shanghainese immigrants in Hong Kong.
This is a meal in one dish and makes a quick, satisfying lunch. It serves 2 as a meal, 4 or more if served with other Chinese dishes.
Cut the pork evenly into thin slices, then into slivers. Add the marinade ingredients and mix well.
Bring a pan of water to the boil. Add the noodles and cook for 2 minutes (fresh Shanghai and udon noodles are already half-cooked when you buy them, which is why this doesn't take long). Turn the cooked noodles into a colander and cool under the cold tap. Shake them dry. Drip over 1/2 tablespoon oil and stir in thoroughly to prevent sticking.
Heat 1 tablespoon of the oil in a seasoned wok over a high flame. Add the pork strips and stir-fry swiftly to separate them. When they are just cooked, remove from the wok and set aside. Clean and re-season the wok if necessary, then return it to a high flame with the remaining oil. Add the noodles and stir-fry until piping hot, adding both soy sauces and seasoning with salt and pepper. Add the bok choy or spinach and continue to stir-fry briefly until wilted. Finally, stir in the pork. Serve.