Step 1

Grate half the onion and finely chop the other half. Combine the grated onion, mince, rice, Worcestershire sauce and half the garlic in a bowl. Season. Use clean hands to mix until evenly combined. Roll level tablespoonfuls of mixture into balls. Place on a baking tray. Place in the fridge to chill.

Step 2

Heat the oil in a saucepan over medium heat. Add the finely chopped onion and cook for 3 minutes or until tender. Stir in the remaining garlic and cook for 1 minute or until aromatic. Add the passata and stock. Stir to combine and bring to a simmer. Season.

Step 3

Transfer the tomato mixture to a slow cooker. Add the meatballs to the sauce and gently turn to coat. Cover and cook on LOW for 5 hours. Sprinkle with parsley to serve.