Start by mixing the meat with the marinade ingredients and set aside for 20 minutes while you prepare the rest of the components.
Heat oil in a wok over medium heat. Add the ginger and star anise, and cook for 30 seconds.
Add the garlic, chilies (if using) and scallions, and stir-fry for one minute.
Add the pork and turn up the heat to high. Stir-fry until the pork is opaque. Then spread the pork out in a single layer on the wok’s surface to brown the meat (30 seconds to a minute).
Stir in the green beans and cook for a couple minutes.
Add the dark soy sauce, light soy sauce and sugar. Stir everything together and add water.
Place the cooked noodles on top of this mixture.
Mix everything together to coat the noodles with sauce. The sauce should be soaked into the noodles very quickly. Serve immediately.