Put the onions, courgettes, leeks, garlic and celery into a pot with a couple of inches of water. Put the lid on the pot and cook over a low heat for 15 minutes.
Add the quinoa to the pot with the stock and cook for a further 10 minutes. (Remember to cook the quinoa as per the packet instructions.)
Then blend with a stick blender until you reach your desired consistency.
Ladle into warm soup bowls or divide into portions and freeze.