Cut the ends of the scallions, remove the outer leaves and cut them into pieces. Peel and cut the potatoes. Put the scallions and potatoes in a pot. Add a drizzle of extra virgin olive oil and a pinch of salt. Cook for a few minutes.
Cover them with the vegetable broth and let cook for about 20 minutes.
Add the milk and blend.
Add water and vinegar into a saucepan and heat until it is almost boiling. With a spoon, make a small swirl in the water and crack the egg into the water. Let it cook for 2 minutes and, very carefully, take it out with the spoon.
To finish, serve the hot cream in individual bowls accompanied by one poached egg on top.
Servings 4