How to Make It
In a large ovenproof saucepan, heat the olive oil. Add the onion, carrots and garlic and cook over moderate heat, stirring occasionally, until the onion is softened and translucent, about 8 minutes. Stir in the tomato paste and cook until lightly caramelized, about 3 minutes. Add the bay leaf, oregano, tomatoes and crushed red pepper and bring to a simmer. Cook over moderately low heat, stirring occasionally, until slightly thickened, 15 minutes. Season with salt and keep at a bare simmer.
Preheat the oven to 400°. In a large bowl, combine all of the ingredients except the Grana Padano and mix by hand until well incorporated. Using a 1 1/2-ounce ice cream scoop (3 tablespoons), scoop 24 meatballs (1 1/2 inches in diameter) and roll into neat balls.
Add the meatballs to the simmering tomato sauce and bring to a boil. Braise in the oven until firm and cooked through, about 30 minutes. Discard the bay leaf and oregano sprigs. Serve the meatballs and sauce with Grana Padano on the side.