Ingredients:

  • 2 (6 oz / 170g) Ahi tuna steaks
  • 2 tbsp (12g) toasted sesame seeds
  • 1 tbsp (15ml) neutral oil
  • 1/2 tsp (3g) kosher salt
  • 1/4 tsp (1g) cracked black pepper
  • 4 tbsp (57g) unsalted butter, chilled and cubed
  • 1 tbsp (15g) wasabi paste
  • 1 tsp (5ml) soy sauce
  • 1 tsp (5ml) fresh lemon juice
  • 1 tsp (5ml) rice vinegar

Instructions:

  1. Pat the tuna steaks completely dry using paper towels. Season both sides with salt and pepper. Press the flat sides of the steaks firmly into the toasted sesame seeds until a thick, even coating is achieved.
  2. Heat the neutral oil in a cast iron skillet over high heat until it just begins to smoke. Carefully place the tuna in the pan and sear for exactly 60–90 seconds per side to ensure a deep mahogany crust while the center remains raw.
  3. Remove tuna to a plate. Reduce skillet heat to low. In a small bowl, whisk together the soy sauce, lemon juice, rice vinegar, and wasabi paste.
  4. Slowly whisk the soy-lemon-wasabi mixture into the pan, then add the chilled butter one cube at a time, whisking constantly until the sauce is thick, glossy, and velvety.