A No-Cooking Meal Stars Ceviche AS an antidote to a sweltering day, a lime-marinated seafood salad is the ultimate summertime ice-box preparation. There is virtually no cooking involved, just a little shopping and chopping. In Central and South America, it is served everywhere. Excellent for hot weather, it is light, spicy and refreshing - good any time of day with an ice-cold beer. Ceviche, as it is usually called, comes in countless glorious variations, but all begin with a sprinkling of salt and a generous squeeze of some kind of citrus, usually sweet limes or a combination of other citrus fruit. The process is simple: bathe hand-chopped raw fish or shellfish in a lime juice mixture until it becomes firm and opaque, giving a gently cooked feel while adding flavor (though some cooks favor a very brief marinade for a nearly raw ceviche). Derived originally from an ancient Peruvian dish (and Peru is still the champion, many concede), ceviche is found virtually everywhere across the Americas, from the coastal regions of Chile to Guatemala to Mexico. Chopped onions and hot chiles are a given in most renditions, as well as cilantro and tomato. In some soupy versions called coctel de ceviche, tomato or clam juice is added. For my ceviche verde, I add diced raw green tomatillos, but there are all sorts of possibilities. Ideally, you have a good fish market or fishmonger to advise you on a sustainable choice for your salad. Halibut or snapper can be good options, but use whatever firm-fleshed fillets are available, and insist they be spanking fresh. You have to decide only whether you want your ceviche barely cooked, in which case you'll give it a short marinade (say, 30 minutes), or if you prefer a firmer texture, let it marinate an hour or more. Drain the fish, add the onions and half the chopped chiles and taste it. It should be quite kicky, so you may need to adjust for the proper spicy balance. But wait to add the cilantro and a final squeeze of lime until just before serving. Will your ceviche be an appetizer with drinks, a first course or a light meal? With drinks, simply offer a bowl of chilled ceviche, some toothpicks and a basket of good tortilla chips. Otherwise, it's nice to make individual composed plates, piling a spoonful of ceviche onto a crisp tostada, then surrounding it with lettuce leaves, radishes and avocado slices.