Ceviche is a traditional seafood dish from Peru that requires no cooking, just marinating. The citric acid of citrus fruits will cause the proteins of the seafood to become denatured, essentially pickling the fish. The seafood should "cook" at least 3 hours, but if the pieces are cut small enough you can often get away with a 2-hour marination time. Just make sure the fish is no longer translucent in the center if you're not using sashimi-grade. Just about any type of fish or combination of fish can be used in this recipe: scallops, white fleshed fish, tuna, etc...Ginger and/or fresh squeezed orange juice also make delicious additions.