Combine the pork with the marinade ingredients and set aside. Combine the ingredients for the stir-fry sauce. Heat a large pot of water over high heat. When boiling, add the noodles and use tongs to gently shake the noodles apart. As soon as they become loose, drain and transfer the noodles to a large bowl or tray. Heat the vegetable oil in a large wok or frying pan over high heat. Add the garlic and the marinated pork. Spread the pork out in the pan so that it has as much contact with the hot pan as possible. Sear for a minute or so then stir-fry and sear again. When the pork is almost cooked, add the shitake mushrooms and stir-fry for half a minute. Then add the cabbage and toss for another half a minute. Then add the choy sum and toss for another half a minute. Add the noodles and the stir-fry sauce and mix until everything is well combined. Serve warm.