Heat your tablespoon of oil in a large saucepan and add your chopped tomatoes, chopped courgettes and garlic. Put a lid on and let it cook on a gentle heat for 5 minutes.
Sprinkle over the flour and stir to mix it all in.Let is cook for 2 minutes.
Add the stock. Put the lid back on and let it simmer for 20 minutes.
Meanwhile, prepare your chard. Remove the leaves from the stems and set aside. Chop up the stems as you would celery into small slices. Heat the remaining oil in a small frying pan and add the chard. Add your herbs and gently stir fry for 6-8 minutes until cooked through but still with a little crunch.
When the main soup is ready, blitz with a handheld blender and season well.
Roll up your chard leaves into a sort of rough sausage and slice them thinly. Add these to your soup along with your cooked chard stems. Let this cook for another 5 minutes and then serve your stoup.