To save time, you can find frozen gua bao buns at Asian grocery stores: simply reheat them in a steamer for 8 to 10 minutes. Homemade ones are still much better.Suan cai (酸菜, Taiwanese pickled mustard greens) and doubanjiang are available at Asian grocery stores. If you can't find suan cai, well-rinsed sauerkraut that is then stir-fried comes close, but doesn't quite match it. Doubanjiang can be replaced with a mild fermented chili paste.Shaoxing wine can be replaced with rice wine or, failing that, with dry sherry. Rock sugar gives the braise a glossy, lacquered finish: with brown sugar, the color will be a little less deep.The ground peanuts can be served plain or lightly sweetened. For the classic Taiwanese version, mix them with a little sugar and add some both before and after the meat; they flavor the pork and balance its fattiness.