Pat the tuna steaks dry with a paper towel. Place on a plate or inside a plastic bag. Mix the soy sauce (2 tbsp), toasted sesame oil (1 tbsp), honey (1 tbsp) kosher salt (1/2 tsp), pepper (1/4 tsp), and cayenne pepper (1/4 tsp) until honey is fully dissolved. Pour over the tuna steaks and turn over to coat completely. Optional: allow to marinate 10-30 minutes in the refrigerator. Heat a medium skillet (preferably non-stick or a well-seasoned cast iron skillet) on high until very hot. Add canola oil (1 tbsp) to the hot pan. Sear the tuna for 2 minutes on each side for medium rare (1.5 minutes on each side for rare; 3 on each side for medium). Remove to a cutting board and allow to rest for at least 3 minutes. Slice into 1/2 inch slices and serve garnished with green onions, toasted sesame seeds, and a squeeze of fresh lime juice, if desired. Seaweed salad also goes well with the tuna.