First off, heat the olive oil in a pan and saute the onions until translucent, to make a yummy caramelised onion.
Add a bit of water, turn up the heat and fry the onions until brown and dry. Add the balsamic vinegar, lower the heat and cook until soft and caramelised. Set aside.
Meanwhile, add the veggies to a roasting tray and drizzle with olive oil. Place a few sprigs of herbs in there too, and roast until soft for about 40 min at 190 degrees Celcius.
Once you have all your elements ready, simply pop the rotis in a baking tray straight to the hot oven for about a minute to crisp up a little.
Remove from the oven and spread with homemade tomato sauce (see recipe above in write up) or any other tomato sauce or relish you wish.
Next top with roasted veggies and sliced mozzarella.
Grill for another 5 minutes until the cheese is melted. Serve immediately.