In a small bowl, whisk together the sesame oil, soy sauce, grated ginger, honey, and minced garlic until well combined.
Place the tuna steaks in a shallow dish and pour the marinade over them, ensuring they are well coated. Cover and refrigerate for at least 30 minutes to allow the flavors to meld.
Heat a non-stick skillet or grill pan over medium-high heat.
Remove the tuna from the marinade, allowing excess to drip off, and season both sides with salt and pepper.
Sprinkle sesame seeds evenly over both sides of the tuna steaks.
Add the tuna to the hot skillet and sear for about 1-2 minutes on each side for rare, or longer if desired.
Remove the tuna from the skillet and let it rest for a minute before slicing.
Serve the sliced tuna on a plate, garnished with sliced green onions and any remaining marinade drizzled on top.