Instructions

  1. Melt butter in heavy large pot over medium heat.
  2. Add 9onions and saute until very tender and pale golden, about 25 minutes.
  3. Add garlic, and stir 1 minute.
  4. Add broth and potato and bring to boil.
  5. Reduce heat; cover and simmer until potato is very tender, about 25 minutes.
  6. Cool slightly.
  7. Working in batches, puree soup in blender.
  8. Return to pot.
  9. Stir in cream, sherry and thyme.
  10. Simmer about 10 minutes.
  11. Season with salt and pepper.
  12. Sprinkle with chives.