YU BO'S TWICE-COOKED PORK

Steps:

• Simmer pork:
• Put pork in a 5-quart pot and cover with cold water by 2 inches. Bring to a boil, skimming foam as necessary, then add ginger and scallion. Reduce heat and simmer, uncovered, until pork is just cooked through (it should no longer be pink inside), about 1 hour. Drain in a colander and cool (pork will be easier to slice).
• Cut pork crosswise into 1/8-inch-thick slices (discarding any bones) and pat dry.
• Stir-fry pork and leeks:
• Wash white and pale green sliced leeks in a bowl of cold water, then lift out and drain well. Pat dry. If using Chinese leek greens, wash separately in same manner.
• Stir together chile bean sauce, cayenne, black beans, and sweet bean sauce in a small bowl.
• Stir together wine and soy sauce in a small cup.
• Heat a wok over high heat until a bead of water dropped onto cooking surface evaporates immediately. Add 1 tablespoon oil, swirling it around wok, and heat until it begins to smoke. Carefully add pork slices (oil will spit) and cook, letting slices lie flat against wok to brown but stirring occasionally, until golden, about 3 minutes. Transfer pork with a slotted spoon to a bowl.
• Add remaining tablespoon oil to wok and heat over high heat until it begins to smoke. Add chile mixture and stir-fry 1 minute.
• Return pork to wok and stir-fry until coated with chile mixture. Add wine-soy mixture and stir-fry until pork is coated. Add white and pale green parts of either kind of leek and stir-fry until almost crisp-tender, 2 to 3 minutes. Add Chinese leek greens if using. Continue to stir-fry until leeks are crisp-tender (and greens are just wilted), about 1 minute.