Pour olive oil into the pot and then add the onions and sauté over low to medium heat until translucent but not browned (about 10 minutes).
Add garlic to the pot and sauté with the onions for a further minute.
Next add the pork and veal mince to the pot and fry over medium high heat for about 5 minutes, until all mince is evenly browned. Use a wooden spoon to break up the mince so that it doesn't clump. Mince should be very fine with no clumps when browned.
Now add the tomato passata, water and tomato paste and stir thoroughly for a minute so that all ingredients are well combined.
Add basil, salt and cloves and cinnamon to the pot (put cloves and cinnamon into a little tea infuser so you don't have to fish them out later).
Cover the pot with the lid and simmer on very low heat for 2½ hours, stirring occasionally so that the sauce doesn't stick to the bottom of the pot.
Take the lid off and continue to cook over very low heat for half an hour.
Serve with your choice of pasta and sprinkle generously with freshly grated parmesan cheese.