For the sauce, heat some olive oil in a saucepan and fry the garlic with the basil stalks (without leaves) and the chilli flakes. Add tomatoes and vinegar and let simmer for about half an hour. Then fish out the chilli pepper.
For the meatballs, mix all the ingredients together and form small balls. Heat some olive oil in a pan and fry the balls brown. Add the fat to the sauce and simmer for another 10 minutes.
During this time, cook the pasta until al dente.
Drain the pasta and pour over the sauce with meatballs. Add the butter, parmesan and basil leaves and serve immediately.