Cut the pumpkin, potato and leek into small pieces and sauté in clarified butter until translucent. Crush caraway seeds, coriander and peppercorns in a mortar and pour over the vegetables together with the sprig of thyme. Simmer in a closed pot for about 20 minutes over low heat. Deglaze with the broth and bring to the boil. Let it steep for another 20 minutes with the pot open.
Puree the vegetables, season with salt and pepper. Before serving, fold in the cream and sprinkle with parsley.