Preheat oven to 350? Fahrenheit. ?Scrub the pumpkin, pierce through the flesh at the top a few times with a sharp knife and bake in the oven until it softens enough to cut easily, about 20 to 25 minutes. ?Cut the softened pumpkin into quarters to cool and then scoop out the seeds and strings. Slice into wedges, peel with a sharp paring knife and cut into 1 1/2 inch cubes.
Heat the oil in a large stockpot over medium heat. ?Add leek and onion and saut? for three minutes. Cover tightly and cook for about 15 more minutes, stirring occasionally, until clear and soft. ?
Add in pumpkin and potato cubes, broth, bay leaf, curry powder, nutmeg, ginger and white pepper. Bring to a boil, cover and reduce heat to low. ?Cook 15 to 20 minutes until the pumpkin and potatoes are soft.
Remove bay leaf and puree the soup with an immersion blender or in small batches using a food processor or blender. ?Use extreme caution if using the latter two options.?If pureeing in batches, transfer the batches of pureed soup into a new large pot. ?You may refrigerate the soup at this point if you are going to serve it later.
Before serving, heat soup over medium heat. ?When it starts to bubble, reduce heat to low and stir in milk and salt. When soup is hot, taste and adjust seasonings and thin with additional milk if it?s too thick. Immediately ladle into bowls and garnish with a dollop of cr?me fraiche and a sprinkling of toasted pumpkin seeds, if desired.