1In 3-quart saucepan, heat oil over medium heat. Cook onion and celery in oil 4 to 5 minutes, stirring occasionally, until tender.
2Stir in remaining ingredients except fresh thyme. Heat to boiling; reduce heat. Cover; simmer 15 to 20 minutes or until sweet potato is tender.
3Into blender or food processor, add half of the soup. Cover; blend on medium speed 1 to 2 minutes or until smooth; return to saucepan. Blend remaining soup. Heat blended soup 1 to 2 minutes or until hot. Garnish with fresh thyme.