Does anybody who's had this dish know how to make it? Or can you suggest a cookbook that might have a similar recipe in it? I moved from Ninth Ave. about five months ago, and pork with sour string beans, which I estimate I had at least weekly when I lived a few blocks from Grand Szechuan International in Hell's Kitchen, has been on my mind to a disturbing degree. Not quite sure where to start, though, with the sour part. Ideas?