Clean the leek, remove only the hard green leaves, use the rest. Remove the peel from the shallots or onions and chop coarsely. Cut the leek into rings, the previously peeled potatoes into cubes. Sauté everything in butter, then fill up with the beef broth and simmer gently for 25 minutes with the lid closed. Cool down a bit and blend in a hand mixer. Later pour the wine and whipped cream and season the soup lightly with pepper. Rinse the chervil, toss dry and reserve a few leaves for garnish. Heat the soup, mix with the chopped chervil and pour into preheated soup bowls. Serve garnished with chervil leaves. Serve with fresh white bread.