No one ever said that an afternoon snack had to be light, or even healthy, for that matter. For instance, say it's a Saturday following a rather eventful Friday night. You awoke a bit later than usual and have made it through those first couple of errands. Now you're looking for something more substantial, something downright artery-clogging. "Elote con todo, por favor." Say those magic words to Ericetta, the chipper woman who tends the umbrella-covered cart (from 11 a.m. to 9 p.m. most days) just outside the entrance to Fiesta. She'll load up a cup with corn, Parmesan cheese, sour cream, mayonnaise and lime (be sure to get the lime) and hand it off to you to add desired amounts of chile sauce and lemon pepper. Sound absurd? Mix it on up and dive into a fattening heaven that'll have you down for a recuperative nap in no time?but not before you grab a refreshing agua fresca from the inside caf? counter. An afternoon snack--OK, fine, an afternoon meal, for less than a fiver.