Rinse the sushi rice until the water runs mostly clear.
Cook the rice, then season it with rice vinegar, sugar, and salt.
Press the warm rice into a lined dish and refrigerate until firm.
Cut the chilled rice block into small rectangles.
Fry the rice pieces in hot oil until crispy and golden.
Mix the diced tuna with mayo, sriracha, sesame oil, soy sauce, scallions, and sesame seeds.
Top each crispy rice piece with a slice of avocado and a spoonful of spicy tuna.
Garnish with jalapeño slices, scallions, and sesame seeds before serving.
