Rinse the sushi rice under cold water until the water runs clear.

In a medium saucepan, combine the rinsed rice, water, and salt. Bring to a boil, then reduce heat to low, cover, and simmer for 18-20 minutes until the rice is tender and water is absorbed.

Remove from heat and let it sit covered for 10 minutes.

In a small bowl, mix the rice vinegar and sugar until dissolved.

Once the rice has cooled slightly, gently fold in the vinegar mixture.

Spread the rice on a baking sheet to cool completely.

In a large bowl, combine the tuna, avocado, cucumber, cherry tomatoes, and green onions.

In a separate small bowl, whisk together the sesame oil, soy sauce, lime juice, and a pinch of salt and pepper.

Pour the dressing over the salad and toss gently to combine.

To serve, scoop a portion of the cooled rice onto a plate and top with the tuna avocado mixture. Sprinkle with sesame seeds.