Ingredients:

  • 2 sushi-grade ahi tuna steaks, 6–8 oz (170–225 g) each, about 3/4–1 inch (2–2.5 cm) thick
  • Kosher salt, 1/4–1/2 teaspoon (to taste)
  • Freshly ground black pepper, 1/4 teaspoon
  • 1/3 cup mixed sesame seeds (black + white) (≈50 g)
  • 1 teaspoon toasted sesame oil (for brushing; optional)
  • 1–2 tablespoons neutral high-smoke oil (canola, grapeseed, or avocado) (15–30 ml)
  • 4 cups packed baby arugula (≈120 g)
  • 1 small shallot, very thinly sliced (or 2 scallion whites), optional
  • 1 small ripe avocado, sliced, optional
  • 2 tablespoons low-sodium soy sauce (30 ml)
  • 1 tablespoon rice vinegar (15 ml)
  • 1 tablespoon fresh lemon juice or yuzu (15 ml)
  • 1 tablespoon toasted sesame oil (15 ml)
  • 1 teaspoon honey or maple syrup (5 ml)
  • 1 small garlic clove, minced, optional
  • Pinch of red pepper flakes, optional
  • 2 tablespoons extra-virgin olive oil (30 ml) — or 1 tablespoon if you want it lighter
  • Thinly sliced scallions (green parts), 1 tablespoon, optional garnish
  • Additional toasted sesame seeds, 1 teaspoon, optional garnish
  • Lime or lemon wedges, for serving
  • Wasabi mayo or ponzu on the side (optional)

Instructions:

  1. Pat tuna dry with paper towels; season lightly with kosher salt and freshly ground black pepper.
  2. Spread mixed sesame seeds in a shallow dish. Press each tuna steak firmly into the seeds to coat the sides (leave top and bottom lightly covered or fully coated as preferred). Optionally brush a little toasted sesame oil on the tuna before pressing and chill 10–15 minutes to help seeds adhere.
  3. Whisk soy sauce, rice vinegar, lemon juice (or yuzu), toasted sesame oil, honey (or maple), minced garlic (if using), pinch of red pepper flakes (if using) and olive oil in a small bowl or jar; taste and adjust seasoning.
  4. Toss arugula (and sliced shallot and avocado if using) with enough dressing to coat lightly; arrange on warmed or room-temperature plates and set aside.
  5. Heat a heavy skillet (cast-iron or stainless) over high heat until very hot. Add neutral high-smoke oil and swirl to coat.
  6. Place sesame-crusted tuna in the hot pan and press briefly for full contact. Sear 30–45 seconds per side for very rare, or 1–1.5 minutes per side for medium-rare; sear edges 10–20 seconds if desired. Internal temperature guide: rare 115–120°F (46–49°C), medium-rare ~125°F (52°C).
  7. Remove tuna to a cutting board and rest 1–2 minutes to allow carryover warming.
  8. Slice tuna crosswise into 1/4-inch (6 mm) slices. Arrange slices over or alongside dressed arugula, sprinkle with thinly sliced scallions and extra sesame seeds, and serve immediately with lemon or lime wedges and optional wasabi mayo or ponzu.