Ensure the risotto is fully cooked and cooled.
Take a small portion of risotto and flatten it in your palm.
Place a cube of mozzarella in the center and mold the rice around it to form a ball.
Repeat with remaining risotto and cheese until you have a dozen balls.
Set up a breading station with flour, beaten eggs, and breadcrumbs.
Dredge each arancini in flour, shaking off excess.
Dip in the beaten eggs, letting excess drip off.
Coat thoroughly with breadcrumbs.
Heat oil in a deep pan over medium heat until hot.
Fry the arancini in batches until golden brown, about 3-4 minutes each.