Step 1Melt the butter in a soup pot over medium heat. Add the leeks, celery, carrots, ginger, jalapeno and thyme. Season well with salt. Cook, stirring, until vegetables are wilted, about 15 minutes.
Step 2Stir in the squash and stock and bring to a boil. Reduce the heat to medium-low, cover and simmer 20 to 30 minutes, or until all the vegetables are falling-apart soft.
Step 3Remove the pot from the heat and let the contents cool slightly. Working in batches, puree the mixture in a blender until smooth.
Step 4Return the puree to a clean pot and stir in the cream. Heat through gently; do not allow to boil. Season with additional salt if needed and with pepper to taste.
Step 5Ladle the soup into bowls, sprinkle with pecans and serve at once. Makes 8 cups.