Pat dry the tuna. Use paper towels to remove excess moisture. This helps the surface sear.

Whisk the marinade. In a small bowl, combine 2 tablespoons soy sauce, 1 teaspoon toasted sesame oil, 1 teaspoon honey, 1 teaspoon lime juice, 1 minced garlic clove (or 1/2 teaspoon garlic powder), and 1/2 teaspoon grated ginger.

Marinate briefly. Add tuna steaks to a shallow dish and spoon the marinade over both sides. Let sit for 10–15 minutes at room temperature. Don’t go longer, or the acids will start to “cure” the exterior.

Preheat the air fryer to 400°F (205°C). Let it heat for 3–5 minutes. A hot basket gives better browning.

Make the wasabi mayo. Stir together 1/3 cup mayo, 1–2 teaspoons wasabi paste (to taste), and 1 teaspoon rice vinegar. Add a pinch of salt. Thin with a splash of water if you want a drizzly sauce.

Oil and season. Lightly brush the tuna with avocado oil and sprinkle with a little salt and pepper. The marinade is salty, so go easy.

Air fry. Place tuna in the basket in a single layer. Cook for 3–4 minutes, flip, then cook 2–3 minutes more for rare to medium-rare (about 115–120°F in the center). Add 1–2 extra minutes for medium.

Rest briefly. Transfer to a plate and rest 2 minutes. This lets juices settle and finish the cook.

Slice and serve. Cut across the grain into thick slices. Drizzle or dollop the wasabi mayo on top. Garnish with sesame seeds and sliced scallions if you like.

Round out the plate. Serve with rice, a crisp cucumber salad, or steamed greens for balance.