My latest transfixion is ceviche, and my favorite part of the dish is what's known as leche de tigre.
Leche de tigre, or tiger's milk, is the Peruvian term for the citrus-based marinade that cures the seafood in a ceviche. Also known as leche de pantera, this leftover fish runoff usually contains lime juice, sliced onion, chiles, salt, and pepper — along with a bit of fish juice.
In Peru, the invigorating potion is often served alongside ceviche in a small glass and believed to be both a hangover cure as well as an aphrodisiac.
Source: Flickr User Carlos Varela