Step by step

1. 1 Cut the tomatoes in half lengthwise.
2. 2 Peel and quarter the onion.
3. 3 Place the tomatoes, onion, and unpeeled garlic cloves on an ovenproof tray.
4. 4 Drizzle with a little olive oil and season with salt and pepper to taste.
5. 5 Bake the vegetables at 225°C for 30 minutes.
6. 6 Take the tray out of the oven and peel the garlic cloves.
7. 7 Blend the tomatoes together with the onion and garlic cloves until you obtain a smooth sauce.
8. 8 Pass the sauce through a food mill to achieve a finer texture.
9. 9 Season the minced beef with salt and pepper and add the egg.
10. 10 Knead well until you obtain a homogeneous mixture.
11. 11 Divide the dough into portions of about 20g and shape them into rounds to form the meatballs.
12. 12 Place the meatballs on an ovenproof tray, making sure they are separated from each other.
13. 13 Drizzle with a little olive oil and bake at 225°C for 10 minutes.
14. 14 Remove the tray from the oven and add the tomato sauce over the meatballs, making sure they are well covered.
15. 15 Return the tray to the oven and cook for another 5 minutes at 225°C.
16. 16 Remove the tray from the oven and add the fresh basil.