The secret to these stuffed rice balls? Make sure your bread crumbs are finely ground in a food processor.
Spread the pre-cooked leftover risotto out on the baking sheet to cool quickly and refrigerate until needed. (The risotto may be made 1 day ahead. When completely cooled, cover with plastic wrap and refrigerate.) Preheat oven to 375 degrees F.2.
Meanwhile, put the panko crumbs on a plate or shallow dish and put the flour on a plate or shallow dish and season the flour with kosher salt. In a medium bowl, whisk the eggs with ⅓ cup water. Using your hands, roll the cooled risotto into balls about the size of a large marble. You will end up with 6-8 arancini.3.
Coat the balls in the flour, then the egg, and then the panko and transfer to a foil-lined baking sheet as you bread them. Lightly spritz with olive oil or Pam spray and bake in preheated oven for 10-15 minutes, or until lightly brown and bubbly.