Pre-heat the oven to 180°C or Gas mark 4.
Grate the parmesan cheese. Cut the mozzarella into 12 equal (10g) pieces.
Peel and crush the garlic. Break the egg into a small bowl and beat lightly.
Place the mince in a mixing bowl and add 2/3 of the parmesan, mozzarella, garlic, chilli flakes, tomato puree, Worcestershire sauce and egg.
Mix the ingredients until thoroughly combined.
Using your hands form the mince into 12 equal meatballs and place in an oven proof dish. Remember to wash your hands thoroughly after handling raw meat.
Cover the dish with cling film and place in the fridge until while you make the sauce.
Peel and finely chop the onion. Peel and crush the garlic.
On a separate chopping board finely slice the bacon.
Fry the bacon and onion for 4 minutes. Add the garlic and cook for a further minute.
Dissolve the stock cube in 200ml of boiling water.
Add the vegetable stock, stir and bring to the boil.
Add the chopped tomatoes and torn basil leaves, stir and remove from the heat.
Remove the meatballs from the fridge and remove the cling film.
Pour the sauce over the meatballs and sprinkle the remaining parmesan on top. Cover with tin foil.
Bake in the oven for 35 minutes before carefully removing the tin foil. Return to the oven and bake for a further 10 minutes.
Serve the meatballs with spaghetti.