Classic Meatballs with Tomato Sauce

Name: Classic Meatballs with Tomato Sauce
Ingredients: Extra-virgin olive oil, for cooking; 2 tablespoons garlic, finely chopped; 1/2 yellow onion, finely diced; 1 sprig fresh rosemary, leaves finely minced; 1 pound ground pork sausage or pork; 8 ounces ground chuck; 8 ounces ground mortadella (or diced into 1/4-inch pieces); 8 ounces ground veal; 1 1/2 cups grated Parmigiano-Reggiano; 1 1/4 cups heavy cream; 1 large egg; 2 tablespoons extra-virgin olive oil; 3 cloves garlic, sliced; Three 28-ounce cans San Marzano tomatoes, run through a food mill or blended in a blender; 1 tablespoon red chile flakes; 10 leaves fresh basil; 1/4 cup grated Pecorino-Romano; Grilled bread, for serving