Heat a heavy skillet or cast-iron pan over high heat until very hot. Add 1 tablespoon neutral oil and swirl. Sear the tuna 30–45 seconds per side for rare (longer if you prefer medium). Rotate the steak to get even crusts; total sear time should be about 1–2 minutes. Remove to a cutting board and let rest 2–3 minutes.

Slice

Using a sharp knife, slice the tuna thinly on the bias into 1/4-inch slices. Arrange on a plate and tent loosely with foil while you finish the salad.

Marinade / Dressing

Make Dressing

In a bowl, whisk together soy sauce, lime juice, rice vinegar, honey, sesame oil, grated ginger, and minced garlic until honey dissolves. If you want heat, whisk in chili flakes (about 1/4 tsp). Taste and adjust: add more lime for brightness, more honey for sweetness, or more soy for saltiness.

Reserve Some Dressing

Reserve about 2 tablespoons of the dressing to drizzle over the seared tuna slices at the end. Use the remaining dressing to toss the salad base.

Salad Assembly

Combine Salad Ingredients

In a large bowl, combine the mixed salad greens, diced mango, diced pineapple, sliced cucumber, sliced red bell pepper, sliced red onion, chopped cilantro, and green onion.

Dress the Salad

Add the majority of the dressing (reserve 2 tablespoons) to the salad. Toss gently but thoroughly to coat ingredients evenly. Taste and adjust seasoning with a pinch of salt or an extra splash of lime if needed.

Add Avocado

Just before serving, gently fold in the sliced avocado to avoid mashing it.

Finish & Serve

Plate

Divide the dressed salad among 2–3 plates or shallow bowls (depending on portions). Fan the sliced seared ahi tuna over each salad.

Drizzle and Garnish

Drizzle the reserved 2 tablespoons of dressing over the tuna slices. Sprinkle toasted macadamia nuts (or cashews) and toasted sesame seeds over the salad. Add lime wedges on the side for extra acidity.

Serve

Serve immediately so the tuna stays warm/rare and the greens stay crisp.