Preheat oven 200C. Evenly spread the tomatoes and garlic in a single layer in a large roasting tin. Mix the oil, vinegar together. Drizzle over the tomatoes and sprinkle with the dark brown sugar.
2
Roast the tomatoes in the preheated oven for 20min. until tender and lightly charred in places.
3
Remove from the oven and allow to cool slightly. When cool enough to handle, squeeze the softened flesh of the garlic from the papery skins.
4
Place with the charred tomatoes in a strainer over a saucepan, or blend the tomatoes and garlic then put through strainer with the back of a wooden spoon.
5
When all the flesh has been sieved, add the tomato purée / paste and vegetable stock to the pan. Heat gently, stirring occasionally.
6
In a small bowl, beat the yoghurt and basil together and season to taste. Stir the basil yoghurt into the soup. Garnish with basil leaves and serve immediately.