Wash and clean the young onions. Cut away approx. 10 cm from the green ends. Cut the onions into fine rings and sauté in hot oil in a large frying pan for about 5 minutes. Remove 4 tablespoons from pan and save for garnish. Deglaze the onions in the pan with the wine (that is: pour the wine onto the hot onion mixture so that it just fizzes), bring to the boil again briefly, then empty everything into a large pot. Pour in the hot soup and simmer for about a quarter of an hour. Finally, pour the cream into the soup, puree everything with a hand blender, then season with salt and white pepper.