Don't look for perfectly moist hunks of chicken here. They dry out a bit, but that's the point. They'll caramelize and slowly take on the flavors of the chiles. Oddly, the nuggets I forked up the fastest were the slices of celery. These certainly have to be the tastiest bits of celery I've ever encountered.
Though relatively straightforward, this recipe probably looks a little intimidating to the uninitiated. Things like Sichuan peppercorns and chile bean paste are hard to find in regular grocery stores. But there are no real substitutes. Search them out! They cost little, and keep for a long time. Plus you'll be able to whip up something utterly stunning like this in less than 30 minutes.