Tangy Tart Hot & Sweet. That’s the name of model turned Top Chef dictatress Padma Lakshmi’s new cookbook, and that’s just how she behaved before swooning fans last night at her Strand book signing. After donning “serious” glasses to read food-related mini-memoirs from the book, she told the crowd that saying “Please pack your knives and go” to Top Chef’s weekly loser was “the hardest part of my job” … and divulged that men often ask her to say it to them in a dominatrix-y sort of way. (“It creeps me out!” she insisted.) She said the show had knocked down any remaining foodie limits she might have had: “I’ll put anything in my mouth once.” Oh, Padma!