Seared Ahi Sandwich Recipe

Prepare the tuna

Pat the 12 oz ahi tuna dry with paper towels. Trim any sinew and shape into an even rectangular steak roughly 1-inch thick so it cooks uniformly.

Marinate briefly

In a shallow dish combine 2 tbs soy sauce, 1 tsp sesame oil, 1 tbs fresh lime juice, 1 tsp minced garlic, and 1 tsp freshly ground black pepper. Place the tuna in the dish and spoon the marinade over it, turning once. Marinate at room temperature for 10 minutes (do not over-marinate — just enough to flavor the surface). Reserve any remaining marinade for brushing if desired.

On a small plate combine 3 tbs sesame seeds, 3 tsp coarse kosher salt, and 1 tsp black pepper. Press both long faces (top and bottom) of the marinated tuna into the sesame-salt mixture so the seeds cling to the surface and form a thin crust. Lightly press to adhere but do not cover the sides where the tuna will remain exposed (for easier searing).

Split the 2 ciabatta rolls and lightly butter the cut sides with the 2 tsp softened butter. Heat a skillet or griddle over medium heat and toast the buttered cut sides until golden, 1–2 minutes. Remove and keep warm.

In a small bowl combine 3 tbs mayonnaise, 1 tsp sriracha, and 0.5 tsp lime zest. Stir until smooth. Set aside.

Thinly slice the cucumber and red onion. Halve, pit, and thinly slice the avocado. Toss the greens lightly with a pinch of salt and a squeeze of lime if desired. Have pickled ginger and cilantro ready if using.

Sear the tuna

Heat a heavy skillet (cast-iron preferred) over high heat until very hot. Add 1 tsp neutral oil and swirl. Carefully place the crusted tuna in the pan and press gently to ensure seed contact. Sear 45–60 seconds on the first side for rare to medium-rare (resulting in a pink center), then flip and sear 30–45 seconds on the other side. For a more done center, add 15–30 seconds per side. Avoid overcooking — ahi is best served rare to medium-rare.

Rest and slice

Transfer the seared tuna to a cutting board and let rest 2 minutes. Using a sharp knife, slice the tuna crosswise into 3/4-inch thick slices (or thinner if preferred).

Assemble the sandwiches

Spread the sriracha-lime mayo evenly on both toasted roll halves. On the bottom half layer mixed greens, a few cucumber slices, and a couple of red onion rings. Fan avocado slices over the vegetables. Arrange seared tuna slices on top of the avocado. Add pickled ginger and cilantro if using. Finish with a squeeze of lime or lemon over the tuna, then place the top roll half on the sandwich.

Cut sandwiches in half if desired and serve immediately while the tuna is warm and the bread is toasted. Provide extra lime/lemon wedges and remaining soy or sriracha on the side.