Method

1. Slice all the tomatoes in half and place flesh side up on a baking tray. Generously sprinkle with salt and pepper, then turn over to flesh side down.
2. Drizzle tomatoes with olive oil, then add the garlic and thyme.
3. Roast in the oven for 30mins at 200°C. For a richer flavour, try roasting at a lower temperature, for longer. Remove from the oven.
4. In a frying pan, melt the butter and fry the onions over medium heat until caramelized.
5. Stir in the tomato puree and cook for a minute or so, then deglaze the pan with a splash of balsamic vinegar.
6. Pour in the roasted tomatoes and garlic, add your stock and basil, then allow to simmer.
7. Blend with a hand blender until desired texture, using more stock to thin out as necessary.