1Rinse the sushi rice 2-3 times until the water runs clear. Drain and let rest for 20 minutes.
2In a saucepan, combine 3 cups of sushi rice with 4 cups of water. Bring to a boil over medium heat, then cover and simmer for 12 minutes. Remove from heat and let stand covered for 10 minutes.
3In a small bowl, mix 4 tablespoons of rice vinegar, 1 teaspoon of sugar, and 1 teaspoon of salt. Pour this mixture over the cooked rice and gently mix. Let the rice cool to room temperature.
4Prepare the fillings: slice the avocado and cucumber into thin strips. Cut the salmon fillet into thin slices. Drain the canned tuna.
5Mix the tuna with 2 tablespoons of mayonnaise and 1 tablespoon of sriracha sauce for a spicy tuna filling.
6Lay a sheet of nori on a bamboo mat or parchment paper. Wet your fingers and spread a thin layer of sushi rice over the nori, leaving a border at the top.
7Sprinkle sesame seeds over the rice. Flip the nori so the rice is facing down.
8Spread a thin layer of cream cheese, then add shrimp tempura, avocado, and cucumber strips.
9Roll the sushi tightly using the mat or parchment paper. Slice into even pieces.
10For fried sushi: dip the sushi roll in a thick batter made from 3 tablespoons of flour, 0.25 cup of water, and a pinch of salt. Coat with panko breadcrumbs.
11Heat frying oil in a pan. Fry the coated sushi rolls until golden and crispy. Drain on paper towels and slice.
12Mix mayonnaise and sriracha sauce to make a spicy topping. Drizzle over the sushi.
13Serve the sushi with soy sauce and, if desired, sprinkle with fried onions.