1In 4-quart saucepan, heat oil over medium heat. Add onion and leek to oil; cook 4 minutes, stirring frequently, until soft. Stir in broth, sweet potatoes and apple pieces. Heat to boiling; reduce heat. Cover and simmer about 20 minutes or until sweet potatoes are tender.
2Meanwhile, in small microwavable bowl, place broccoli and water. Cover with plastic wrap and microwave on High 1 minute 30 seconds or until crisp-tender; set aside.
3In blender or food processor, place about one-third of soup mixture. Cover; blend on high speed until smooth, stopping blender to scrape side if necessary. Pour into large bowl. Repeat 2 times more with remaining soup mixture. Pour soup back into saucepan; stir in broccoli. Cover and heat over low heat about 10 minutes or until hot.
4Divide soup evenly among 6 bowls. To serve, top each serving with 1 tablespoon sour cream and 2 apple slices.