Cook the brown rice as per the packet instructions, cutting short the cooking time by five minutes. Rinse and set aside the rice.
Put the carrots and celery into a large soup pot with about 3cm of water and cook for 5-6 minutes until soft.
Add the stock, spring greens, prunes, kale and brown rice then cook for a further 10 minutes.
Ladle into warm soup bowls and serve with whole grain or whole meal brown bread.