- Heat oil and margarine in a saucepan over medium-high heat; add onion and cook for 2 minutes.
- Add leeks and potatoes and cook 3 minutes. Pour in chicken broth and bring to a boil. Reduce heat to low; cover and cook for 30 minutes.
- Transfer soup to a blender jar and process until smooth and creamy in texture.
- Return soup to the saucepan and pour in creamy soy preparation, stirring well. Reheat gently.
- Garnish with fresh chives and freshly ground pepper just before serving.
: Replace leeks by 250 mL (1 cup) cubed celery root.