1 Cook leeks in butter: Melt the butter in a large saucepan over medium heat. Add the leeks and cook, stirring occasionally, for 5 minutes, or until leeks are soft but not browned.
2 Add broth, potatoes, white pepper, simmer 25 min: Add chicken broth, potatoes and white pepper. Bring to a boil over medium high heat.
Reduce heat. Cover and simmer 25 minutes or until vegetables are very tender.
3 Purée the soup: Using an immersion blender, or a standing blender working in batches, process until smooth. (If using a standing blender, do not fill your blender more than a third full with hot soup.)
4 Add ham, cream, seasonings: Stir in the diced ham and enough cream, milk, or half and half, or stock to thin the soup to desired consistency.
Season to taste with salt. Garnish with parsley, chives or dill.