Preheat the oven to 180 degrees Celsius. Cut the Meatballs horizontally into two equal slices. Cut the eggplant into equal slices, place on a baking sheet and sprinkle with salt so that it draws moisture out during 20 minutes. Pat dry with paper towels. Oil the aubergine and grill in a grill pan for about 2 minutes on each side. Cut the zucchini into equal slices thickness of half a centimeter, oil them and grill in a grill pan for about 2 minutes on each side (the pan must be very hot). Season with salt and pepper. Cut the tomato into equal slices and season with pepper. Create turrets of aubergine, zucchini, tomato and slices Meatball (in that order). Drop some olive oil over the slices. Finish with the vegetables. Insert a toothpick through the turrets so they will not to fall. Put the vegetable pies in a baking dish and cook them for about 10 minutes in the preheated oven. Meanwhile, make the tomato sauce with chopped onion and clove of crushed garlic in the oil to fry. Add the tomato paste and fruit it so it can acidify. Put finally the tomatoes in the pan and warm it. Season with salt and pepper. When the sauce is ready, you can put some fresh basil leaves by stirring. Remove vegetables tarts from the oven and spoon over some tomato sauce. Serve with fresh pasta or a piece of peasant bread.