Cook the pancetta in a heavy based pan over a medium heat in the oil for about 5 minutes stirring frequently. Add the meatballs and cook for another 5 minutes or so until the meatballs change colour and the pancetta pieces are nice and crispy.
Meanwhile finely chop the vegetables.
Remove the meat to a plate, then gently fry the onions for 5 minutes in the remaining oil (add a little more if needed).
Put in the remaining vegetables, stir, then cover and gently sauté for another 5 minutes.
Meanwhile measure and mix the herbs & spices in a small bowl.
Add the herbs, spices and passata to the pan. Half fill the passata container with water, shake around and pour into the pan.
Season to taste and crumble in the stock cube.
Bring to the boil, stirring frequently, then cover and simmer gently for half an hour.
Add the chopped coriander and, with a stick blender, whizz the sauce until smooth and thick.
Return the meatballs to the pan and cook for another 10 or 15 minutes.
Serve with boiled rice or pasta. Scatter the crispy pancetta over each serving.