This is an easy soup for the coming cooler months; and squash will be less expensive then it is in the summertime.. Some gourmet's put apples in with this soup which is great also, you can add the apple with the pear if you like- I like it with just the pears and squash.
In a large pot over medium heat add the oil,and onion and cook, stirring until tender. Stir in broth, squash, pears, and spices. Heat to boiling; reduce heat. Cover and simmer for 10-15 minutes or until squash is fork tender.
Puree soup in batches in food processor or blender. Return pureed soup to pot. Stir in milk. Reheat, stirring frequently, until very warm , but do not boil. Garnish with sour cream and chopped nuts.