Kiam chai boi, a sour vegetable stew, is a Malaysian leftovers dish. What stale bread is to panzanella, cooked vegetables from a roast are to bubble and squeak, and lechon is to paksiw, meat (usually pork) doggy-bagged home after a Chinese wedding banquet or other celebration is to kiam chai boi.
Wedding banquet invitations don't come along every day, so we usually get our kiam chai boi fix in PJ's Section 17, at a coffee shop that also houses a stall serving prosaic pan meen and another dishing up a laudable not-Thai tom yam.
Like all kiam chai boi this stew features mustard greens two ways - pickled and fresh - and is soured with assam keping (lit. 'sour slice'), an ingredient that's often mistakenly described as tamarind peel but is in fact the dried flesh of a hard, green-skinned fruit called buah assam gelugor.
The broth is rich and meaty but pork pieces aren't prevalent, which in our opinion is a good thing. This is a side dish, after all. Copious coins of ginger, along with plenty of dried red chilies, lend this version considerable hot to balance the sour.
What to eat with kiam chai boi? This vendor offers a number of options, the best of which is soy-braised tofu: firm-skinned, creamy-centered blocks of flavorful bean curd (if you think bean curd has no flavor you haven't been eating the right bean curd) infused throughout with the warm spiciness of their salty, star anise-scented braising liquid.
Bean sprouts sauced with garlic and soy are a fine accompaniment.
Tofu and kiam chai boi make for an awfully light meal, so adding an order of superb moist and crisp-skinned roast chicken isn't at all gluttonous. The bird is doused with sweet dark soy sauce and served with stock-boiled rice, a small bowl of clear soup with a leaf or two of vegetable, and a sinus-clearing sourish chili sauce.
Roast pork (char yoke) is also on offer here, though its fat layer lacks requisite melting-ness, suggesting that it is not this cook's forte. No matter. It's really the kiam chai boi and tofu first, roast chicken following at close second, that inspire repeated visits to this stall, both to eat in and take away.
Kiam chai boi, soy-braised tofu, roast chicken and pork vendor at Kedai Kopi Wah Cheong, Jalan 17/29, Section 17, Petaling Jaya. Early morning-230p or so. Closed every other Thursday.