- 1 avocado
- 1 clove garlic, chopped
- 1 tablespoon crème fraîche or sour cream
- 2 serrano chiles, seeded, finely chopped, divided
- 2 tablespoons fresh lime juice, divided
- Kosher salt
- 4 ounces sashimi-grade skinless, boneless yellowtail fillet
- 2 teaspoons olive oil
- 1 teaspoon fish sauce
- 1 teaspoon finely chopped shallot
- 1/2 teaspoon finely grated peeled ginger
- 1/2 teaspoon yuzu kosho
- 1 radish, trimmed, thinly sliced
- Cilantro leaves with tender stems and thin fancy crackers or crispbread (for serving)
- Mash avocado with garlic, crème fraîche, half of serranos, and 1 Tbsp. lime juice in a small bowl until mixture is mostly smooth; season with salt.
- Hold your knife at a 45° angle and slice fish with the grain into 1/2″ slices (use a sharp blade and aim for one long, clean stroke). Cut each slice crosswise into 1/2″ pieces.
- Combine oil, fish sauce, shallot, ginger, yuzu kosho, remaining serrano, and remaining 1 Tbsp. lime juice in a medium bowl. Add yellowtail, season with salt, and gently toss crudo to combine.
- Spread avocado mixture on plates. Top with yellowtail, radish, and cilantro. Serve with crackers.