Toss the pork fillet in the rice wine or brandy, 1 tablespoon of soy sauce, sesame oil and cornflour to coat. Marinate for 30 minutes. Meanwhile, cook the rice following pack instructions.
Mix together the remaining soy sauce with the oyster sauce, ginger and garlic to make a thick sauce. Bring a saucepan of water to the boil and blanch the broccoli for 3 minutes. Drain and run under cold water to cool.
Heat the groundnut oil in a large wok over a high heat and stir-fry half the pork for a few minutes until just cooked. Remove from the wok with a slotted spoon and set aside. Repeat with the remaining pork.
Wipe the wok with kitchen paper and return to the heat. Add the broccoli and sugar snap peas with 3 tablespoons of water and stir-fry for 4 minutes. Add the pak choi and 1 tablespoon of water and cook for another 2 minutes. Return the meat to the pan with the sauce, toss with the greens and heat for 1 or 2 minutes more. Serve with the rice.