Rinse the Arborio rice under cold water until the water runs clear to remove excess starch.

Set a pot over medium heat, add vegetable broth, and bring to a boil.

Once boiling, add the rinsed rice, stir, cover, and simmer for 15-18 minutes.

Remove from heat, keep covered for an additional 5 minutes, fluff with a fork, and spread on a plate to cool.

In a mixing bowl, combine cooled rice, Parmesan cheese, parsley, and egg. Season with salt and pepper and mix well.

In another bowl, flake the tuna, mix with mayonnaise, lemon juice, onion, and celery. Season with salt and pepper.

Take a scoop of rice mixture, flatten it, place a spoonful of tuna mixture in the center, and mold into a ball.

Roll each rice ball in flour and then in breadcrumbs.

Heat vegetable oil in a skillet to 350°F, and fry the rice balls in batches for 3-4 minutes until golden.

Transfer fried rice balls to a rack or paper towels to drain excess oil and serve hot.