Can demonstration cooking sell-out a stadium? Probably not, but considering how much people shelled out for Food Network's old lady, uhm, Grande Dame last week, Top Chef's tour of 20 cities might generate a little buzz. I think it'll depend on who the "four cheftestants" turn out to be. Anyone buying a ticket — Sept. 20, here in Tampa — for a Lisa, Mark, Nimma and Nikki cook-a-long? Me neither.