Step 1: Prepare the Red Onion. Place the very thinly sliced red onion in a bowl of ice water for 5-10 minutes. This will mellow its flavor. Drain thoroughly and pat dry before use.
Step 2: Prepare the Fish. Ensure your fish is very fresh and cold. Cut the fish into uniform 1/2-inch cubes. Place the diced fish in a non-reactive bowl (glass or ceramic). Season lightly with salt and gently toss.
Step 3: Make the Leche de Tigre Base. In a blender, combine about 1/4 of the diced fish, 1/4 of the sliced red onion, minced garlic, grated ginger, aji amarillo paste, minced aji limo/serrano pepper, and half of the lime juice. Blend until completely smooth. Strain the mixture through a fine-mesh sieve into a clean bowl, pressing down on the solids to extract as much liquid as possible. This is your "leche de tigre" base. Discard the solids.
Step 4: Combine and Marinate. Add the remaining diced fish and the rest of the thinly sliced red onion to the bowl with the leche de tigre base. Add the remaining lime juice and the chopped cilantro. Gently stir to ensure all the fish is coated with the marinade. Taste and adjust salt if necessary.
Step 5: "Cook" the Ceviche. Let the fish marinate for about 15-20 minutes in the refrigerator. The acidity of the lime juice will denature the proteins in the fish, causing it to turn opaque, similar to cooking with heat. Do not over-marinate, as the fish can become tough.
Step 6: Serve. Serve the **Ceviche Recipe** immediately in chilled bowls or glasses, garnished with fresh cilantro. Traditionally served with slices of cooked sweet potato, boiled corn kernels (choclo), and toasted corn kernels (cancha). Enjoy your delicious and refreshing **Ceviche Recipe**!