In a large saucepan cook onion in hot butter over medium heat about 10 minutes or until tender and translucent. Stir in curry powder, ginger, and salt. Cook 30 seconds more.
Stir in chicken broth and water; bring to boiling. Add squash. Return to boiling; reduce heat. Simmer, covered, about 40 minutes or until squash is tender.
Cool soup slightly. Transfer half the soup at a time to a blender or food processor. Blend or process until smooth. Return all soup to saucepan. Stir in coconut milk, half-and-half, and chopped cilantro. Heat through. Top with fresh cilantro. Makes 6 side-dish servings.