Preheat your oven to 220C / 200C fan / gas mark 7 / 425F.
Place all the meatball ingredients in a large bowl and mix together thoroughly with your hands (you can do this with a wooden spoon, if you prefer, but it’s much better done with your hands!)
Roll mixture into balls of roughly 25g (1 oz). This should make approximately 44 balls. (Tip – there’s no need to weigh every single meatball! Simply weigh out the first one, then try to make all the other balls roughly the same size by eye.)
Place the balls on a baking tray lined with lightly greased foil and cook in the pre-heated oven for 20 minutes. There’s no need to turn them.
While the meatballs are baking in the oven, make the tomato sauce. Place the oil and diced onion in a wide saucepan or a deep frying pan (a sauté pan is ideal) and cook over a low heat with the lid on for 3 minutes, or until softened but not browned. Add the garlic and fry gently for 2 more minutes, stirring occasionally.
Add the passata, basil, salt and pepper and bring to the boil. Turn the heat down again and simmer for 10 minutes.
Add the oven-baked meatballs to the sauce and simmer for a further 5 minutes.
Serve over spaghetti and with a sprinkling of parmesan and a scatter of basil leaves.
Suitable for freezing.Nutrition information is approximate and meant as a guideline only.