At some point, New Orleans gets so damn hot you’re ready to let someone else do the cooking. Lately one of my top candidates for that job has been citrus. That’s the alchemy of ceviche, the way citric acid from lime and other fruit transforms raw seafood without going anywhere near the stove. The texture tightens, its surface whitens and the result is a bracingly bright, utterly light seafood dish that feels so in synch with the season.