Roasting the tomatoes and peppers for this soup really adds depth of flavour to the end result. The addition of a basil-flavoured yogurt and a fresh-tasting tomato tartare complete a great soup.
Preheat the oven to 220°C/425°F/gas mark 7. Place the tomatoes, peppers, onion, garlic and thyme in a roasting tin, spoon over the olive oil and season. Roast them for