Heat the butter or oil in a large pot over a medium/low heat, then add the onion and cook, stirring for a few minutes or until soft and transparent but not browned. Stir in the garlic and cook for a further minute.

Stir in the chopped broccoli stalk and florets, as well as the vegetable stock and water. Bring nearly to the boil, then reduce the heat and simmer for 20 minutes.

Using a blender (in batches) or a hand held immersion blender and puree the broccoli soup with the butter.

Return the soup to the pot (if you used a blender), and stir in the milk. Gently reheat the soup and season with pepper - you probably won’t need salt as stock can be salty.