Seared Ahi Tuna Recipe

Trim and pat dry

Trim any connective tissue or dark streaks from the ahi loin and pat the fish dry with paper towels. Dry surface ensures better sear and sesame seed adhesion.

Make marinade

In a shallow dish combine soy sauce, sesame oil, lime juice, grated ginger, minced garlic, salt, and black pepper. Stir to combine.

Marinate briefly

Place the tuna in the dish and spoon half of the marinade over the top. Let rest at room temperature for 10 minutes, turning once to coat. Do not marinate longer than 20 minutes — we want flavor on the surface but to keep the interior rare.

Prepare sesame crust

On a plate combine the white and black sesame seeds and spread into an even layer. Remove the tuna from the marinade, letting excess drip off, and press each side and ends of the loin into the sesame mixture so the seeds adhere to the exterior. Pat gently to secure.

Heat pan

Heat a heavy skillet (cast iron preferred) over high heat until very hot, about 2–3 minutes. Add the neutral oil and swirl to coat. The oil should shimmer but not smoke heavily.

Sear the tuna

Carefully place the sesame-crusted tuna in the hot skillet. Sear for 30–45 seconds on each of the two longer sides to develop a deep golden crust, and 15–20 seconds on each short end. Aim for a dark sear while keeping the center rare (raw-looking pink). Total sear time will be about 1.5–2 minutes depending on thickness. If using butter, add it to the pan for the last 10 seconds and spoon the foaming butter over the tuna for added flavor.

Rest

Transfer the tuna to a cutting board and let rest for 2 minutes — this relaxes the juices and makes slicing cleaner.

Prepare sauce

In a small bowl whisk together the ponzu (or soy), remaining marinade that wasn’t used directly on the fish (if any), and the wasabi paste until smooth. Taste and adjust: more ponzu/soy for salt, more lime if desired for brightness, or more wasabi for heat.

Slice and plate

Using a very sharp knife, slice the tuna across the grain into 1/4-inch to 1/2-inch slices. Fan the slices on a serving plate or alongside a bed of greens/steamed rice.

Finish and serve

Drizzle a small amount of the ponzu-wasabi sauce over the tuna slices or serve it on the side for dipping. Sprinkle sliced scallions and scatter pickled ginger on the plate. Serve immediately with lime wedges for squeezing over the fish.