How to Make It
In a large bowl, soak the bread crumbs in the milk for 15 minutes. Add the ground pork, parsley, half of the garlic, 1 1/2 tablespoons of salt and 1 teaspoon of pepper; knead gently to combine. Refrigerate for 1 hour.
Preheat the oven to 300°. Form the meat mixture into 1 1/2-inch balls and arrange them in a lightly oiled roasting pan. Bake for about 30 minutes, until just cooked through.
Meanwhile, in a saucepan, heat the 1/3 cup of oil. Add the onion, the remaining garlic and a generous pinch of salt. Cook over moderate heat until the onion is softened, 10 minutes. Add the oregano and cook until fragrant, about 2 minutes. Add the tomatoes and bring to a simmer. Cook over moderately low heat until slightly reduced, about 20 minutes. Transfer to a blender and puree until almost smooth. Season the sauce with salt and pepper.
Pour the sauce over the meatballs, cover tightly with foil and bake for 2 hours. Drizzle the meatballs with oil, sprinkle with cheese and serve.