Grill or barbecue the peppers, then cut them into thin slices. This can be done well ahead.
Chop the onion and garlic. Cut the tomatoes in half.
Heat the oil in a frying pan and cook the meatballs, until brown, then transfer them to plate.
Add more oil to the pan, if needed. Gently sauté the onion for 5 minutes, then add the garlic. Stir for a few seconds, then add the tomatoes, paprika and marjoram. Sautee for 5 minutes, then add the vinegar and deglaze the pan. Add the sugar too, if the tomatoes are not very ripe.
Add a glass of water, season with salt and pepper and reduce the sauce.
Add the parsley, grilled pepper slices and sun-blushed tomatoes. Warm through and serve.