People who use pumpkins only for jack-o-lanterns or pumpkin pie are missing out on a great vegetable. Pumpkins are, after all, squash-- and squash can be made into a delicious warming soup.
You can use canned pumpkin for this soup (unsweetened and unseasoned), or you can bake, peel, and boil pumpkins left from Halloween. Drain and mash them so that what you have is mostly solid pumpkin pulp, and you have a vegetable you can freeze for later use. (You can also use pureed squash for this soup.)
A cold winter day is just the time to make use of it. Defrost your pumpkin pulp, and put it into a pot, adding one cup chicken stock or chicken broth for every two cups of mashed pumpkin. Bring to a simmer over medium heat, and add either salt and pepper to taste, or about a teaspoon of Vegeta® if you have it (Vegeta® is a mixed vegetable and herb seasoning, not unlike chicken bullion powder or cubes, which you could add instead). You can also add a little nutmeg if you like it. Stir well, and let it simmer for a few minutes.
Just before serving, mix in about a tablespoon of sour cream (or light sour cream). When it has been thoroughly mixed in, remove the soup from the heat and serve immediately. It is low in calories and high in fiber, and both filling and warming on a cold day.