Heat the wok over a high flame for 1 minute. Add the oil, and when the oil is very hot (this will take just a few seconds; pass your hand over it to feel the heat, or look for a wisp of smoke), add the salt and garlic to flavor the oil: A common mistake is to skimp on oil in stir-frying vegetables, which makes them dry out and burn. Use enough to coat the vegetables thinly but thoroughly.
Remove the garlic when it has browned. Add the bok choy and Stir-fry, working smoothly and rapidly, keeping the vegetables moving.
Taste a piece of bok choy to see if it is done. It should be crisp but should not taste raw. When it reaches that stage, transfer it to a serving dish. Stir-fried vegetables should glisten with brilliant color; never let them fade in the wok.
Chinese mustard greens are very good prepared in a similar manner. Substituted 4¼-inch-thick slices of fresh ginger root for the garlic and 1½poundsmustard green stems, cut into 1-inch pieces, for bok choy and proceed as above.
May be prepared in advance and served cold.
Suggested Beverage: Dry Sauvignon Blanc or Sancerre