This soup can be served hot as a traditional soup, but I also love it served cold for lunch on a hot day. It's mild - not spicy at all, but with lots of flavor.
- In pan large enough to hold all ingredients, saute onions and celery in butter for 5 minutes.
- Add potatoes, water and bouillon. Heat to boiling.
- Simmer, covered, for 30 minutes.
- Place 1/2 potato and liquid mixture in blender, cover and process on low just until smooth.
- Pour into serving bowl and repeat with remaining potato and liquid mixture.
- Whisk in remaining ingredients, except taco sauce, until smooth. serve warm or chill 2 hours before serving.
- Garnish with taco sauce.