Preheat oven to 400 degrees F.
Prick potatoes with a fork and on a baking sheet bake in middle of oven 1 1/2 hours, or until very soft. Scoop potato flesh into a bowl.
In a food processor puree potatoes with remaining ingredients, adding up to 1/4 cup water to reach desired consistency.
Serve dip with chips or crudites.
Recipe courtesy of Gourmet Magazine