Mix together the pork and marinade ingredients (the cornstarch, light and dark soy sauce, wine, and sugar). Set aside while you prepare the other ingredients.

When ready to cook, heat a wok over high heat until just starting to smoke. Add 1 tablespoon of oil around the perimeter of the wok. Add the pork, and stir-fry until browned. Reduce the heat to medium, remove the pork from the wok and set aside. Add the remaining oil to the wok and stir-fry the mushrooms for 2 minutes. Break up the noodles gently with your hands, and add them to the wok with the mushrooms.

Add the soy sauces and sugar. Stir-fry everything together until the noodles get an even, deep brown color. If you’re not seeing the color you want, add a little more dark soy sauce.

Add the leafy greens (choy sum and baby bok choy both work well), along with the pork. Mix in with the noodles until the greens are wilted. Serve immediately.