In a large mixing bowl, combine the fish
with the onion
juice, and chile; season with salt and pepper. Toss gently to combine, being sure to coat the fish with the lime juice. Cover and refrigerate for 30 to 45 minutes, do not marinate longer or the acids from the lime will make the fish mushy. Serve cold with cilantro
and canchita on top. .
*Note: The aji amarillo is traditional chile in Peru and available at any Latin grocery but not in many mainstream supermarkets. In substitute you can use a habanero or any other hot chile.