Sweat the onion and potato cubes in 3 tablespoon clarified butter and deglaze with the vegetable stock. Add the marjoram and star anise. Pepper, salt, simmer for 20 minutes. Remove the marjoram and the star anise and puree the soup.
Fry the porcini mushrooms and apple wedges one after the other in 2 tablespoon clarified butter and remove.
Roughly dice the fish and fry in 2 tablespoons clarified butter for 2-3 minutes. Salt.
Whip the cream and add to the soup with the apple wedges, mushrooms and halibut. Season again with pepper and salt. Serve with a little watercress.