Plot: Who’s that guy walking towards us through the heat on a Mexican beach? It’s Rick, and he’s about to prove a tasty point about ceviche, the traditional Mexican seafood salad marinated in lime and chiles: it’s so ancient, so elemental and so easy, you don’t even need a kitchen to make it. And so saying, Rick prepares Classic Ceviche right on the beach, using nothing more than a lime to “cook” the fish