Cut squash in half; discard seeds. Place squash cut side down in a 15x10x1-in. baking pan coated with cooking spray. Bake at 400° for 40-50 minutes or until tender. Cool slightly; scoop out flesh and set aside., In a Dutch oven, saute onion in oil until tender. Add the curry, garlic, ginger and salt; cook 1 minute longer. Stir in the broth, pears and squash. Bring to a boil. Reduce heat; simmer, uncovered, for 30 minutes. Cool slightly., Puree soup using an immersion blender. Or cool slightly and puree soup in batches in a blender until smooth. Return all to the pan; add cream and heat through. Top with balsamic vinegar and chives if desired.