Stir together the soy sauce and rice wine or sherry in a bowl, add the pork and toss well. Marinate for 15 minutes.
Cook the pasta in a large saucepan of lightly salted boiling water for 10 minutes, or according to the packet instructions, until al dente. Drain and cool under cold running water.
Meanwhile, heat 2 teaspoons of the oil in a wok or large frying pan over a moderate heat, add the garlic and ginger and stir-fry for 15 seconds. Add the pork and marinade and stir-fry for 4 minutes until cooked. Remove to a plate.
Pour the remaining oil into the wok, add the buk choy and stir-fry for 2 minutes. Next, add the peas and spring onions, stir-fry for 1 minute, then pour in the stock and oyster sauce. Bring to the boil. Stir the cornflour mixture into the wok, reduce the heat and simmer for 30 seconds, or until the sauce is thickened.
Add the pork and linguine, heat through for 1–2 minutes, then stir in the bean sprouts and sesame oil. Toss together and serve at once.