Heat the olive oil in a large saucepan and cook the onion for 5 to 8 minutes over a gentle heat until almost softened but not browned.
Add the garlic, celery, carrots, bay leaf and thyme and cook for a further 6 minutes, stirring occasionally, making sure the vegetables don't stick to the base of the pan.
Add the chopped tomatoes and sugar and season well with salt and pepper cook for a few minutes, then stir in the passata and vegetable stock, bring to a simmer, cover with a lid and cook for 3o to 40 minutes, until all the vegetables are tender.
Remove the bay leaf and thyme, and then blend the soup in a liquidizer or food processor (we used to and sometimes still put the soup through a mouli as sometimes the tomato seeds when over processed can be bitter), this will probably have to be done in two batches.
Pour the soup into a clean saucepan, passing it through a sieve if you want it really smooth the stir in the cream and check the seasoning and pour into bowls top with finely shredded basil if required and serve with fresh crusty buttered bread
Serve and Enjoy!