In a rice cooker, combine the rinsed sushi rice and water. Cook according to the rice cooker instructions.

Once cooked, transfer the rice to a large bowl. In a small bowl, mix rice vinegar, sugar, and salt until dissolved. Pour over the rice and gently fold to combine. Allow to cool.

Heat vegetable oil in a frying pan over medium heat. Once hot, scoop about 1/4 cup of rice mixture and flatten it into a patty.

Fry each patty for about 3-4 minutes on each side until golden brown and crispy. Remove and drain on paper towels.

In a mixing bowl, combine the diced tuna, mayonnaise, sriracha, soy sauce, sesame oil, and green onion. Mix well.

Top each crispy rice patty with a generous spoonful of the spicy tuna mixture.

Garnish with black sesame seeds and microgreens before serving.