- Bring broth to boil in medium-size saucepan. Add asparagus, onion, celery salt and pepper. Reduce heat; cover and simmer, 20 minutes, or until asparagus is very tender.
- Stir in soymilk and butter until butter melts. Remove from heat; cool 10 minutes.
- Process half of asparagus mixture in covered blender container until smooth. Return to saucepan. Repeat with remaining mixture.
- Cook, stirring occasionally, over medium heat until heated through.