Directions:
1) In large saucepan, over medium-high heat, melt butter. Add onion; cook 2 to 3 minutes or until onions are slightly softened, stirring frequently.
2) Add squash, water, salsa and bouillon granules. Cover and bring mixture to a boil. Reduce heat to medium-low. Cook 20 to 25 minutes or until squash is fork tender, stirring occasionally. Remove mixture from heat. Let cool for 15 minutes.
3) Place squash mixture in food processor or blender (in serveral small batches, if necessary)and process until smooth. Return pureed squash to saucepan.
4) Add half-and-half, salt, pepper and basil. Cook 4 to 6 minutes or until hot and flavors are blended, stirring constantly. Ladle soup into warm bowls and serve. If desired, place small dollops of sour cream in a circular-fashion on top of soup. Gently run a toothpick through sour cream to create a swirled effect.