Preheat the oven to 350 degrees. Put the pumpkin on a greased baking tray and lightly brush with half the olive oil. Bake for 25 minutes, or until softened and slightly browned around the edges. Heat the remaining oil in a large pan. Cook the onion and cumin for 2 minutes, then add the carrot, parsley, pepper, garlic, and celery and cook for 3 minutes more, stirring frequently. Add the roasted pumpkin and stock. Bring to a boil, then reduce the heat and simmer for 30 minutes. Allow to cool a little, then puree in batches in a blender or food processor. Return the soup to the pan and gently reheat without boiling. Season to taste with salt and cracked black pepper. Top with the parsley and nutmeg before serving. Note: Butternut pumpkin is often used in soups as it has a sweeter flavor than other varieties. Hint: If the soup is too thick, thin it down with a little more stock.