Maybe this is a noob question, but the advice given in the Provisioning writs is to buy unknown recipes from chefs and brewers. But I've been visiting the chef and brewer in Vivec City for several weeks now, and never once have they had any food or drink recipes for sale, never mind the ones I'm looking for. I've only occasionally been able to buy them from the Guild traders, because they seem to specialise in the more exotic/advanced recipes.
Is this a glitch in the game, or is there something I haven't understood?