Preheat oven to 300 degrees. Place pumpkins on a cookie sheet and roast them until slightly shriveled and soft. Allow to cool slightly, the slice in half and carefully scoop out seeds and pulp. Scoop yummy flesh into a bowl. Set aside. In a pot, heat up the pumpkin flesh with the stock and maple syrup until simmering. Mash out the big chunks, the transfer the mixture to a blender or food processor and puree until velvety smooth. Add cream and nutmeg, then blend again. Reheat if you need to and serve in a hollowed-out pumpkin.