Preheat the oven to 180 deg C
Quarter tomatoes and place them on a large roasting tin
Halve or quarter Onions and place in between the tomatoes
Place garlic cloves in the gaps
Pour over Olive oil
Season with Salt, Pepper and Oregano or Mixed Herbs
Place the roasting tray in the oven and roast for 25 minutes
Be careful when removing the tomatoes from the oven as there will be a lot of steam.
Allow tomatoes to cool before placing them in a blender or thermomix and pulsing until the preferred consistency. If you don't like tomato skins, you can remove them quite easily once they've cooled down
You can use this sauce over pasta, in bolognaise, on burgers or you can make it into a soup by blending until smooth.