900g/(2lb) ripe tomatoes
(about 8), halved
1red onion, peeled and thickly sliced
6 large cloves of garlic, peeled
Leaves from 4 sprigs of thyme
1 tsp caster sugar
2 tbsp extra-virgin olive oil
1 tbsp balsamic vinegar
Sea salt and freshly ground black pepper
600ml ( 1 pint ) chicken or veg stock
50 ml ( 2fl oz )double or regular cream
Basil leaves, to serve