lettuce, steamed broccoli and cherry tomatoes as garnish
Combine the tuna, mayonnaise and pepper in a bowl.
Season the rice with the salt and mix well. Spread about 1/3 of the rice onto a sheet of plastic wrap. Place 1/3 of the tuna mixture into the center, then wrap the plastic wrap and the rice around the tuna, squeezing it into a ball shape. Repeat to create 2 more rice balls.
Line a lunch box with lettuce and place the rice balls inside. Garnish with steamed broccoli and cherry tomatoes.