Wash porcini and soak in 500 ml of warm water for about 30 minutes. Peel and finely dice the onion. Steam in hot fat until translucent. Add wine and bring to the boil. Add porcini mushrooms with soaking water and cream.
Also bring to the boil, stir in the sauce thickener. Season soup with salt and pepper. Wash chives, dab dry and cut into small rolls. Just before serving, puree the soup with the cutting stick of the hand mixer.
Put them on soup plates. Sprinkle with chive rolls and parmesan.