Soak 1/3 cup finely diced white onion in ice water 15 minutes; drain. Mix with 1/2 cup each finely diced tomato and chopped cilantro, 1 each seeded minced aji chile and garlic clove, 2 tablespoons white wine vinegar, 1 tablespoon lime juice and 2 teaspoons extra-virgin olive oil. Thin with water. Season with salt.
Photograph by Con Poulos