Gather all ingredients.
In a small mixing bowl add in the sesame seeds.
Add panko bread crumbs with the sesame seeds.
Coat the tuna steak with the sesame and panko mixture.
Add oil to griddle insert, and heat oil.
Place coated tuna steak onto the griddle insert and sear.
Flip tuna steak and pour half of the soy sauce onto the seared side. Cook until the under side is seared as well.
Sear all edges of the tuna steak.
Flip over and pour the remainder of the soy sauce onto the steak.
In another small bowl, add mayo.
Add sriracha to the mayo.
Add honey to the mayo, and mix.
Spread mayo to the bottom of a toasted bun.
Place tuna steak onto bun.
Spread your favorite guacamole onto the tuna steak.
Place tomato on top of guacamole.
Place lettuce on top of the tomato.
Place bun on top of the lettuce. Serve immediately and enjoy!