Peruvian Ceviche (Ceviche Peruano) — Lime-Cured Fish with Ají and Sweet Potato

• 680 gskinless sea bass fillet (sashimi-grade or the freshest firm white fish available, kept very cold)
• 180 mlfresh lime juice (from about 9 to 10 limes, strained)
• 120 gred onion (very thinly sliced)
• 1ají limo chile (seeded and minced; use 2 for a hotter ceviche)
• 1 clovegarlic (finely grated)
• 10 sprigfresh cilantro (leaves chopped, tender stems reserved)
• 9 gfine sea salt
• 6ice cubes (for chilling and rinsing the onion)
• 2orange sweet potatoes (about 450 g total)
• 2ears of Peruvian choclo or large-kernel corn
• 80 gcancha corn nuts
• 4lettuce leaves (optional traditional garnish)

Instructions

1. 1

   Scrub the sweet potatoes and place them in a saucepan with enough water to cover by 3 cm. Simmer for about 25 minutes, until a knife slides through the centers, then drain, cool, peel, and cut into thick rounds.

2. 2

   Bring a second pot of water to a boil and cook the choclo or corn for 8 to 10 minutes, until the kernels are tender but still full and juicy. Drain it well, cut the ears into serving sections, and keep them at room temperature.

3. 3

   Place the sliced red onion in a bowl with cold water and 3 ice cubes for 10 minutes to sharpen its texture and soften its bite. Drain thoroughly, pat dry with a clean towel, and refrigerate until the fish is ready.

4. 4

   Keep the fish over a chilled board or tray and remove any pin bones, dark bloodline, or sinew. Cut it into even 2 cm cubes so the lime cure penetrates quickly and evenly without making the surface mushy.

5. 5

   In a chilled nonreactive bowl, combine the fish, salt, grated garlic, minced ají limo, chopped cilantro leaves, and the remaining 3 ice cubes. Toss gently for 20 seconds, which seasons the fish before the lime juice begins curing it.

6. 6

   Pour in the strained lime juice and fold the fish gently for 1 minute, making sure every cube is coated. Let it stand for 4 to 6 minutes only, until the outside turns opaque while the center remains tender and moist.

7. 7

   Remove and discard the ice cubes, then fold in most of the drained red onion. Taste the curing liquid and adjust with exactly 1 g additional fine sea salt only if the fish tastes underseasoned.

8. 8

   Line each plate with a lettuce leaf if using, then spoon the ceviche and its leche de tigre into shallow bowls or plates. Garnish with the remaining onion and serve immediately with sweet potato rounds, corn sections, and cancha on the side.