3 slices white bread (stale is fine)
1/3 cup milk
450 g ground pork or veal
450 g ground beef
½ cup finely chopped onion
1 ¼ cups finely grated Parmesan
¼ cup chopped parsley
2 garlic cloves, finely chopped
1 tbs kosher salt
1 tbs black pepper
Olive oil, for frying
5 cups tomato sauce
14 fresh mozzarella, torn into bite-size pieces
Heat oven to 200°C. Remove crusts from bread slices and discard.
Tear remaining bread into small pieces and place in a small bowl. Pour milk over bread and let stand until liquid is almost absorbed, 5 to 10 minutes.
In a large bowl, combine pork or veal, beef, soaked bread, onion, ¼ cup Parmesan, the parsley, the garlic, the salt and the pepper until just combined.
Form meat into golf-ball-size rounds. (You should have about 25 meatballs.)
Fill a large skillet with 0.5cm oil. Place over medium-high heat.
When oil is hot, fry meatballs in batches, turning occasionally, until golden brown, 8 to 10 minutes per batch.
Transfer fried meatballs to a paper towel-lined plate.
Spoon a thin layer of sauce over the bottom of a 23x33cm baking pan.
Sprinkle one-third of the Parmesan over sauce.
Scatter half the meatballs over the Parmesan and top with half the mozzarella pieces.
Top with half of the remaining sauce, sprinkle with another third of the Parmesan, and repeat layering, ending with a final layer of sauce and Parmesan.
Transfer pan to oven and bake until cheese is golden and casserole is bubbling, about 40 minutes.
Let cool a few minutes before serving.