Delicious Summer Basil and Courgette Soup

I just thought I'd share this delicious recipe, great for a summer lunch, a picnic or a starter.
I imagine a lot of us have courgettes (zucchini) coming out of our ears at this time of year and it seems to have been a particularly prolific harvest this summer.
This soup can be served hot or cold.  If you're serving it cold and not watching your waistline a swirl of cream on top is delicious!
It can also be made substituting the basil for mint (or any other herb you like I imagine). 

Ingredients:

2 tbsp olive oil
1 onion, chopped *
1kg courgettes, roughly chopped
1/2 tsp dried basil
1 - 1.3l good vegetable stock (Marigold vegetable bouillon is good)
4 - 5 sprigs of fresh basil
4 tbsp single cream *

* optional ingredients, I didn't use the onion as Al is allergic and see above regarding the cream!

Method:

1. Heat the olive oil in a large saucepan, add the onion (if using) and cook gently for about 2-3 minutes until softened.  
2. Add the courgettes and dried basil. Cover and cook over a gentle heat for about 10 minutes, stirring occasionally, until the courgettes are softened but not coloured.
3. Add the stock to the pan and bring to the boil, then reduce the heat to a gentle simmer.  Add the fresh basil to the pan, cover the pan and simmer gently for 20 minutes or until the courgettes are very tender.
4. Remove from the heat and allow to rest for a few minutes.  Process the mixture in small batches in a liquidiser or food processor until smooth. Pour into a bowls and serve immediately, decorated with a basil leaf and seasoned to taste with salt and pepper.
5. Alternatively, leave to cool, then cover and chill for at least 4 hours (or overnight).  To serve, taste and season with salt and pepper. Serve in chilled soup plates with a spoonful of cream drizzled in the middle.