Saute leeks, potatoes, celery, and carrots in a little water until leeks begin to soften.
Add broth, sherry or dry white wine (optional), and poultry seasoning.
Bring to a boil, cover, and simmer until potatoes are soft.
Puree with an immersion blender or in batches in a regular blender.
Add canned pumpkin and heat through.
Add coconut milk or cashew cream and adjust seasoning, as needed. Heat through and serve with optional toppings, if desired.