Prepare rice: Wash and rinse sushi rice until water is clear. Drain well. Cook according to package instructions. Season with rice wine vinegar. Cover with a damp cloth to prevent drying.

Make filling: In a bowl, combine tuna, sriracha sauce, sesame oil, and scallions.

Roll sushi: Place nori shiny side down on a bamboo mat lined with plastic wrap. Spread rice evenly over nori and sprinkle with sesame seeds if desired. Place tuna mixture along the bottom edge. Roll tightly, pressing gently to keep shape.

Prepare spicy mayo: Whisk mayonnaise, sriracha, and lime juice together until smooth.

Make iced matcha latte: Whisk matcha with hot water until smooth and foamy. Pour into a glass over ice, add milk, and sweeten if desired. Stir well.

Slice rolls: Wet a sharp knife blade and cut each roll into 6–8 pieces, cleaning the knife after every few cuts. Top with spicy mayo or serve on the side.

Serve: Plate sushi with optional wasabi, pickled ginger, and soy sauce for dipping. Enjoy with an iced matcha latte.