So my pal Robert, last heard from here, rears his way-smarter-than-me head again in the pages of Gourmet, this time about how I commandeered his house, backpack full of Greenmarket rhubarb in tow, to make mustard last weekend. I just want to make clear: at no point during said kitchen commandeering did I use the word " isothiocyanates," hence the way-smarter-than-me-ness, but hey, at least I know what they are now.