Heat the grill or a heavy bottomed fry pan to high heat. If I am not grilling the fish, I prefer to use a cast iron pan; it heats higher, and a better crust will develop on the fish.
Coat the fish in sesame oil, sprinkle with salt and pepper and press the sesame seeds onto the fish.
Add the remaining oil to the pan or brush the grill with the oil.
Add the fish to the pan or grill, cook for 30 sec – 1 minute, repeat with all four sides. If the fish does not have four sides, cook each side slightly longer (1-2 min). You want to cook this fish rare. Simply sear the fish, do not cook it through.
Allow fish to rest for at least five minutes or until it reaches room temperature.
Using a very sharp knife, slice into ¼-½ inch slices. Set aside.
In a small bowl, mix together The Glaze Ingredients, pour onto a serving dish.
Lay the tuna slices on top of The Glaze and top each tuna slice with a slice of Jalapeno.