For the Sushi Rice:

• 2 cups short-grain Japanese rice (or Calrose rice as substitute)
• 2½ cups water
• 3 tablespoons rice vinegar
• 1 tablespoon sugar
• 1 teaspoon salt

For the Spicy Tuna Filling:

• 2 cans (5 oz each) high-quality tuna in water, drained
• 3 tablespoons Japanese mayonnaise (or regular mayo)
• 1–2 teaspoons sriracha sauce (adjust to taste)
• ½ teaspoon sesame oil
• 1 green onion, finely chopped
• ½ teaspoon soy sauce

For Assembly:

• Nori (seaweed) sheets, cut into strips
• Salt for hand seasoning
• Small bowl of water for wet hands

Substitution Notes: For gluten-free versions, ensure your soy sauce is tamari. Vegan alternatives can substitute the tuna with finely chopped marinated mushrooms or seasoned chickpea salad. Those avoiding spice can replace sriracha with a touch of rice vinegar for tang without heat.