Diced Fresh Tuna Recipe

Prepare tuna

Place the sushi-grade tuna on a clean cutting board. Using a very sharp knife, trim away any sinew and pat the fish dry with paper towel. Cut the tuna into uniform small dice, about 1/4 inch (6 mm) cubes. Transfer the diced tuna to a medium mixing bowl and keep refrigerated while you prepare other components.

Make the marinade

In a small bowl, whisk together the soy sauce, sesame oil, rice vinegar, lime juice, honey (or agave), grated ginger, and minced garlic until combined and slightly emulsified.

Pour about three-quarters of the marinade over the diced tuna and gently fold to coat all pieces. Reserve the remaining marinade to drizzle at the end or to adjust seasoning. Marinate the tuna in the refrigerator for 5–10 minutes — just long enough to impart flavor without 'cooking' the fish.

While tuna is resting, prepare the vegetables: thinly slice the green onions, very finely mince the shallot, seed and small-dice the cucumber, and if using, seed and small-dice the jalapeño and avocado. Chop the cilantro or chives.

Gently fold the green onion, shallot, cucumber, cilantro (and jalapeño and avocado if using) into the marinated tuna. Combine just until evenly distributed. Taste a small amount and adjust seasoning with the reserved marinade, salt and pepper as needed.

Sprinkle the diced tuna with toasted sesame seeds and a light grind of black pepper. If desired, add a pinch more salt to taste.

Arrange the diced tuna on a chilled plate or shallow bowl. Garnish with extra chopped herbs and serve with lime wedges alongside crisp wonton chips or tortilla chips. Drizzle any remaining reserved marinade lightly over the tuna immediately before serving.

Serve within 10–15 minutes of assembling for best texture and freshness.