Ingredients:

  • 350–400 g Ahi Tuna Steaks (2 pieces, minimum 1.5 in / 4 cm thick, sushi-grade)
  • 1 tbsp (15 ml) High-heat neutral oil (e.g., groundnut or avocado oil)
  • Pinch of Sea salt and freshly cracked black pepper
  • 4 tbsp (60 ml) Low-sodium Soy Sauce (or Tamari)
  • 1 tbsp (15 ml) Fresh lime juice
  • 1 tbsp (15 ml) Mirin (Japanese sweet rice wine) or caster/granulated sugar
  • 1 tsp (5 ml) Toasted sesame oil
  • 1 inch (2.5 cm) piece fresh Ginger, grated finely
  • 1 clove Garlic, minced finely
  • ½ tsp Red pepper flakes (optional)
  • 3 tbsp (45 g) White Sesame Seeds, toasted lightly
  • 1 tbsp (15 g) Black Sesame Seeds

Instructions:

  1. Thoroughly pat the tuna steaks dry using paper towels. In a shallow dish, whisk together the soy sauce, lime juice, mirin, sesame oil, grated ginger, minced garlic, and optional red pepper flakes to create the marinade. Place the tuna in the marinade, ensuring both sides are coated. Marinate for a minimum of 20 minutes and a maximum of 30 minutes. Combine white and black sesame seeds on a separate plate to prep the crust.
  2. Remove the tuna from the marinade (discard the residual marinade). Lightly sprinkle the steaks with salt and pepper. Firmly press all four sides of each tuna steak into the sesame seed mixture until evenly and thoroughly coated. Place a cast iron pan over very high heat for 3–5 minutes until smoking hot. Add 1 tbsp of high-heat oil; it should shimmer immediately.
  3. Carefully place the tuna steaks in the hot pan. Sear for 60–90 seconds per side, aiming for a dark golden brown crust and a cooked perimeter of about ¼ inch (6 mm) thick. Using tongs, sear the remaining two edges for 15–20 seconds each. The total cooking time should be roughly 4–6 minutes.
  4. Immediately remove the tuna from the pan and place it on a wire rack or cutting board. Allow the steaks to rest uncovered for 5 minutes. Using a very sharp knife, slice the tuna against the grain into thin slices (about ⅛ inch or 3 mm thick) and serve immediately.