Cut the pork into finger size strips and put into a shallow dish with the marinade. Set aside for at least 30 minutes but preferably longer.
Bring a large pan of water to the boil and when it is bubbling fiercely add the noodles. Cook according to packet instructions , then drain. Add the stock to the empty pan and bring to a simmer.
Heat a wok over a high heat then pour in the oil. When the oil is hot drop in the pork pieces which you have shaken dry. Pour the marinade into the hot stock.
Cook the pork for 3 minutes until golden brown and lightly crisp. Remove with a slotted spoon and drain on kitchen paper. Turn off the heat.
Ladle the hot stock into deep bowls, add the cooked noodles and pork and eat immediately.