Put the beef, egg, breadcrumbs and herbs into a large bowl. Peel and finely grate the garlic then add to the bowl. Work the mixture together with your hands until thoroughly mixed. Season with salt and pepper. Roll the mixture into 10 equal-sized balls.
Heat the oil in a large frying pan over a medium-high heat. Fry the meatballs in batches for 8 minutes until golden-brown all over. Return all of the meatballs to the pan then pour over the chopped tomatoes, mixed herbs and sugar. Peel and grate the garlic, add to then pan then cook over a medium heat for 8-10 minutes.
While the meatballs are cooking, bring a large pan of salted water to the boil. Add the spaghetti and cook for 10-12 minutes or according to the packet instructions. Just before the spaghetti is ready, add a ladleful of the pasta water to the tomato sauce to thin it down, if necessary.
Drain the spaghetti and add to the pan with the meatballs. Toss to combine then divide between two serving bowls.