Heat the oven to Gas Mark 6, 200°C (400°F). In a large bowl mix together the minced beef, minced pork, beaten egg, breadcrumbs, parsley, cheese and garlic. Season with salt and freshly ground black pepper. With wet hands shape into small meatballs, about 2-3cm in diameter – you should get 14-16 meatballs. Place them in an ovenproof dish big enough for them to sit in one layer. Cook in the oven for 10 minutes while you make the tomato sauce. To make the tomato sauce: Heat a little oil in a frying pan over a medium heat. Add the onion and cook gently until the onion has softened. This will take about 6-8 minutes. Then add the garlic, tomato purée, tomatoes, thyme, chilli flakes and water. Season with salt and freshly ground black pepper. Bring to the boil then turn down the heat and allow the mixture to simmer for a couple of minutes. Pour the sauce over the meatballs. Cover the dish with a lid or tin foil and place it back in the oven for 30 minutes. Cook the pasta in a large saucepan as per the packet instructions. Drain the pasta. Reserve a little of the cooking liquid and return it along with the pasta to the saucepan. When the meatballs are cooked stir them and the sauce gently through the pasta. Taste and season as necessary. Transfer to a large serving bowl, sprinkle over the parsley and cheese and serve along with a green salad.