Cut the tomatoes in half and thinly slice the garlic.
Cook the spaghetti according to the instructions on the package, then drain. Put aside one cup of the cooking water.
Meanwhile, fry the pork until crispy. Add the garlic and chilli flakes. Stir, then add the tomatoes and tomato purée. Sprinkle with sugar and cook for about 5 minutes.
When the tomatoes have softened and a thick tomato sauce is formed, add the drained spaghetti, the chopped parsley and about 3-5 Tbsps of the cooking water. Tear the mozzarella into small pieces, and add to the pasta. Stir and heat through.
Serve with chopped parsley and plenty of ground pepper.