Cut the broccoli florets off the head and peel the stalk and cut into pieces. Peel both with carrot and celery and cut into large pieces. Clean and wash the leek and cut into large pieces. Put everything in a saucepan with the water and cook until the vegetables are soft.
Add salt, pepper, nutmeg and milk and mix with the hand blender. Take the pot off the stove and mix the cold butter into the soup with the hand blender. Season again with salt. Serve immediately.
A herbal baguette (to bake) is enough, which is baked in the oven during the cooking time.