Stir together half the sherry and all the soy sauce, cornflour, sesame oil, sugar and pepper in a small bowl. Add pork. Toss to coat. Marinate at room temperature for 15 minutes.
Heat 1 tbsp oil in large non-stick frying pan or wok over high heat. Add bok choy. Stir-fry 2 minutes. Cover. Cook until wilted, about 2 minutes. Transfer bok choy to a plate. Discard liquid left in frying pan.
Add remaining oil to pan. Add garlic. Sauté 15 seconds. Add the pork mixture and stir-fry until the meat is just cooked through, 3 to 4 minutes. Add bok choy and remaining sherry. Cook until heated through. Serve immediately.
Used different ingredients.
When I tasted the dish at the end I thought it needed a bit more flavour so I added some finely chopped fresh ginger. It improved the taste, but ideally I would have added it earlier in the cooking, either with the meat, or even added it to the marinade. - 09 Jun 2009