Every now and then since December 2004, a good number of us have been getting together at the eGullet Recipe Cook-Off. Click here for the Cook-Off index. For our second Cook-Off, we've chosen char siu bao, or steamed bbq/roast pork buns. You've probably had this dim sum staple many times, often a tough dough encasing a gummy, cloying clump of pork -- . But if you had a good one, you know how ethereal the dough and amazing the double-cooked pork can be. And that's what we're going to be maki