Spicy Yellowtail Sushi Roll

Rinse rice under cold running water until water runs clear.

Combine rice and water in a large saucepan and bring to a boil. Lower heat to a simmer and cook for 10 minutes. Turn off heat and let rice sit without opening the lid for 20 minutes; the remaining steam continues to cook the rice.

Combine rice vinegar and sugar; stir until mostly dissolved. Once rice has finished steaming, fold in vinegar-sugar mixture. Let rice cool, 15 to 20 minutes.

Place one sheet of nori on a work surface with the shiny side down. Place 1/4 of the rice on the nori and spread it around evenly from edge to edge, about 1/4-inch thick. Flip nori over on top of a plastic-covered rolling mat. Repeat with remaining nori and rice.

Chop yellowtail into 1/4-inch cubes. Combine yellowtail, mayonnaise, and Sriracha in a bowl. Place 1/4 of the mixture, along with 1/4 of the cucumber, in a line along one of the short sides of the nori. Roll the mixture inside the nori using the rolling mat. Press roll tightly to form a uniform log. Spread 1/2 tablespoon tobiko in a long thin line across the top of each roll. Press rolls with rolling mat.

Cover rolls with plastic wrap and press with the rolling mat again. Using a very sharp, wet, clean knife, cut each roll into 8 even pieces. Remove plastic wrap, plate, and serve.