For the filling: Crush the tomatoes with an immersion blender.
In a 4-quart pot, heat the olive oil over medium heat. Add the onions and saute for 3 minutes. Add the carrots and celery and cook until tender. Add the beef and pork and cook, breaking up the meat with a spoon, until browned. Add the crushed tomatoes, increase the heat and bring the mixture to a boil. Add the salt and pepper, reduce to a simmer and let cook for 20 minutes. Add the peas and simmer for 10 more minutes. Remove from the heat and spread on a baking sheet to cool.
For the rice: In a 6-quart pot, bring the chicken stock, butter, salt and saffron to a boil. Add the rice and simmer, uncovered, stirring 2 or 3 times, until tender and the liquid is absorbed, about 25 minutes. Remove from the heat and add the grated pecorino and black pepper. Stir to mix well. Spread on a baking sheet to cool.
For the breading: In a large bowl, combine the breadcrumbs, pecorino, salt and pepper.
For assembly: Place the eggs in a shallow bowl and the flour in another shallow bowl. Scoop some rice into 1 hand to make a half a ball. Add 1 teaspoon of the meat filling and 1 teaspoon of the shredded mozzarella. Add more rice on top to form into a ball. Dredge the rice ball in the flour, then the beaten egg and then in the seasoned breadcrumbs. Repeat and assemble more balls with the remaining rice, filling and breading.
Heat the oil in a large pot or deep fryer to 350 degrees F. Fry the rice balls, in batches if necessary, until golden, about 3 minutes.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Sal's Gilbert Pizza, Gilbert, Arizona