Preheat oven to 190C.

Heat 2 tablespoons of the olive oil in a large non-stick frying pan over a medium heat. Add the onions and fry until softened. Add the garlic and chilli and fry for a few minutes longer until the onions have lightly browned. Transfer the onion mix to a bowl and allow to cool slightly. 

In a large mixing bowl, combine half the cooled onion mix, beef and pork, ¼ cup Parmesan, 2 tablespoons of the tomato paste, fresh herbs, fennel seeds, egg, and a generous seasoning of salt and pepper. Combine well, but do not overmix otherwise the meatballs will be tough. Using wet hands, divide the meatballs into 16 equal portions and roll into balls.

Wipe out the frying pan with a paper towel, and heat the remaining tablespoon of olive oil over a medium heat. Gently fry the meatballs in the oil until browned all over, about 5 minutes. Remove the meatballs and arrange in a baking dish large enough to just hold the meatballs in a single layer, coated with the sauce.

Add the remaining onion mix, tomatoes, passata, the remaining 2 tablespoons of tomato paste, wine, sugar and bay leaves to the cooking juices in the frying pan, bring to a simmer, and simmer for 15 minutes until reduced and slightly thickened. Season well with salt and pepper.

Top the meatballs in the baking dish with the sauce. Break the mozzarella into small chunks and scatter evenly over the sauce. Cover with foil and bake for 20 minutes. Remove the foil and return to the oven for 5 minutes until the cheese is golden brown.

Top with shaved Parmesan and serve hot with spaghetti, polenta or crusty bread, a leafy green salad and a glass of Wolf Blass Yellow Label Shiraz.