Top and tail the leek, celery and courgette and chop into thin slices. Chop the broccoli florets into small pieces.
In a large saucepan heat the oil and add all the vegetables. Gentle sweat the vegetables over a medium heat for 15 minutes. Boil the water and prepare the stock by dissolving the stock cube into it. Then add the stock and seasoning, bring to the boil and simmer for 5 minutes
Remove the heat and, using a blender (hand or jug), blend the soup slightly so it remains a good chunky texture.
Pour into a bowl and enjoy!