Dice the peeled onions and bacon. Clean and wash vegetables and cut into thin slices. Peel and wash the potatoes and also cut them into slices.
Fry the bacon and onions in butter. Add vegetables and potatoes and sauté. Pour in the stock, wine and milk and bring to the boil. Season with the herbs, bay leaf, pepper and salt. Cook for 30 minutes
Take out the bay leaf and puree the soup.
Mix the egg yolks with the crème fraiche and stir into the soup. Season with nutmeg, sprinkle with herbs and serve.