Heat the oil in a large saucepan. Add the onion, leek and garlic. Cook gently until soft.
Put the tomatoes in a bowl. Cover with boiling water and leave for 1 minute. Pour off the water and cover tomatoes with cold water. Leave for 1 minute. Peel the tomatoes and chop roughly. Add to the saucepan, Stir in the chicken stock, tomato puree( paste), salt and pepper and a little sugar, if wished. Bring to the boil, cover and simmer for 30 minutes.
Just before serving, break the bread into bite sized pieces and divide between four warmed serving bowls. Stir the basil into the soup and ladle the soup over the bread. Drizzle with a little extra virgin oil and serve.