Rinse the rice 3-4 times under cold water until it runs almost clear. Combine the rinsed rice and cold filtered water in a pot, bring to a boil, and then reduce the heat to the lowest setting. Cover the pot and let it simmer for 12 minutes. Once cooking is complete, allow the rice to steam for an additional 10 minutes without lifting the lid.

Mix together the rice vinegar, sugar, and fine sea salt in a small bowl until dissolved. Once the rice is ready, transfer it to a large bowl and gently fold in the vinegar mixture.

In two separate bowls, mix the plain flour with half the salt and black pepper in one, and the corn flour with the remaining seasonings in another.

Heat the neutral cooking oil in a deep skillet or pot to 350°F (175°C). Coat each chicken strip first in the flour mixture, then in the cornstarch mixture.

Fry the chicken strips for about 3-4 minutes or until they turn golden brown and crispy. Once cooked, drain them on a wire rack.

Place the nori sheet shiny side down on a bamboo mat. Wet your hands and take a handful of prepared rice. Spread an even layer about ¼ inch thick over the nori, leaving a 1-inch border at the top.

Arrange the tempura chicken strips and avocado slices along the bottom third of the rice. Roll tightly, using the mat to guide the sushi into a compact roll.

Slice through with a sharp, wet knife to prevent sticking. Sprinkle with toasted sesame seeds for garnish.