In a small bowl, whisk together the soy sauce, sesame oil, honey, and black pepper.
Place the sushi-grade tuna steak in a shallow dish and pour the marinade over it. Let it marinate for about 15-20 minutes, turning occasionally.
Heat your heavy-bottomed skillet over medium-high heat.
Once the skillet is hot, remove the tuna from the marinade and place it in the skillet. Sear for about 1-2 minutes on each side.
Sprinkle the white sesame seeds over the steak and allow them to toast slightly.
Remove the tuna from the skillet and let it rest for a couple of minutes. Slice it against the grain into thick strips.
Arrange the sliced tuna on a serving plate, drizzle with any reserved marinade, and sprinkle with sliced green onions. Serve with lime wedges.
