Cube and peel uncooked pumpkin. Cut leeks in pieces. Peel and cut potatoes. Combine pumpkin, leeks, potatoes, water and a pinch of salt in a saucepan. Cover and bring to a boil. Simmer over low heat for 30 minutes until veggies are tender. Puree veggies in food processor with liquid. Return to pan. Bring to boil. Simmer for 5 minutes. Stir in milk, reduce heat to low and simmer for 2 minutes. Stir in cream and simmer, add white pepper, nutmeg and salt if needed. Can refrigerate covered for 1 day. Put chopped parsley on top before serving.