In a medium stockpot coat with 1 tablespoon oil, sweat the onion, garlic, and ginger until the onions are translucent. Add the pumpkin and wine and simmer until the wine is reduced by half. Add the chicken stock and bring to a simmer, continue cooking for about 20 minutes until the pumpkin is tender.
In a hot saute pan coated with 1 tablespoon oil, sear the lemon grass and Thai bird chiles until lightly browned, remove from heat.
When the pumpkin is tender, puree smooth using a hand blender or a blender and return to a simmer. Add the sauteed lemon grass, chilies, sugar, kaffir lime leaves (optional), lime juice, and fish sauce. Gently simmer for 20 minutes. Strain the soup through a medium strainer, discarding the solids, and season well with salt and pepper. The soup should be medium in body and may require additional chicken stock or water.
In a small bowl, mix the sour cream with the chives.
PLATING Serve the soup hot with a dollop of sour cream and chives in the center as garnish.
Copyright 2000, Ming Tsai and Tom Berry, All Rights Reserved