Peel and wash the potatoes and cut into small cubes. Peel and finely dice the onion. Heat butter in a pot. Sauté diced onion for 1-2 minutes. Add potatoes, steam for 1-2 minutes, then add peas. Deglaze with stock and 100 g whipped cream
Season with salt, pepper and nutmeg and simmer covered for 15-20 minutes until the potatoes are soft. Wash the chives, shake dry and cut into thin rolls
Puree the soup and pass through a sieve. Bring the soup to the boil again and season to taste. Add half the chives. Lightly whip 5 tablespoons of cream. Arrange soup in bowls and draw streaks on the surface with the cream. Sprinkle with remaining chives and serve immediately