Heat the oil in a saucepan and cook the onion until it becomes transparent. Add the ground peanuts or peanut butter, potatoes and a little stock and mash well. Alternatively, put these ingredients into a blender. Now pour the rest of the stock slowly into the puree, mixing well. Bring the soup to a boil, then let it simmer, covered, for 5-10 minutes. After this, remove the pot from the heat and season. Sprinkle the chives on top before serving.