The following recipe is from "Cooking with Daniel Boulud," by noted New York chef Daniel Boulud (Random House, 1993, $40), who notes in the introduction that "this soup can be made into a more complete meal by adding slices of cooked lobster or shrimp."
Warm the chicken stock over medium heat. Melt the butter in a cast-iron pot over medium-low heat. Add the onions, curry powder and saffron and sweat for 2 minutes, stirring often. Add the sliced apple and sweat for another 5 minutes, stirring often. Add the cauliflower and warm chicken stock and bring to a boil. Boil until the cauliflower is tender when pierced with a knife, approximately 20 minutes. Add the cream and cook for 3 more minutes. Salt and pepper to taste.
Transfer the soup in batches to a blender or food processor and puree at high speed until very smooth. Keep warm until ready to serve or refrigerate when cool and reheat just before serving.