Heat olive oil in a saucepan over medium heat. Add onion and garlic and stir occasionally. Cook until golden brown.
Add passata, sugar, salt and pepper and stir through.
Cook on low heat for 45 minutes, until the sugo has thickened and is fragrant. Add basil once the sugo is cooked.
Prepare the meatballs while the sauce is cooking. Combine breadcrumbs and milk in a small bowl. Set aside for 10-15 minutes.
To a large bowl add the mince, the breadcrumb mixture, and the remaining meatball ingredients except for the oil, and carefully combine with a fork.
Form meatballs from the mixture with your hands to the desired size, being careful not to compress or overwork the mixture.
Heat a heavy-based pan to medium heat. Add enough oil to cover the base of the pan. Once the oil has heated, add the meatballs, leaving enough space in between.
Sear on both sides, then reduce the heat to low and fry for approximately 10 minutes or until meatballs are cooked through and browned.
Cook the pasta in well-salted boiling water, according to packet instructions. Once al dente, transfer the pasta to a heated pan, along with the meatballs and a few spoonfuls of the sugo. Toss to combine, coating every strand of pasta with the sugo.
Sprinkle with Chilli Salt to taste and serve with grated Parmesan cheese as desired.