1. Heat the butter in a pan over a medium heat and gently fry the onion for 3-4 minutes, until softened. 2. Add the potato and broccoli to the pan and stir. Add the chicken stock and bring the mixture to a simmer. Simmer for 8-10 minutes, or until the vegetables are tender, then stir in 2 tbsp of the cream. 3. Blend the mixture with a stick blender until smooth. 4. Serve the soup in a bowl with the remaining creaum drizzled over the top.