1 pound (1 large or 2 small) Idaho potatoes, washed well and cut into 1-inch chunks
Bring 3 cups of water to boil in a pot with a steamer insert or use a collapsible basket. Reduce the heat to a brisk simmer, add the potatoes. Make sure water does not touch the potatoes. Steam for 14-16 minutes, or until tender when pierced with a fork.
Transfer the potatoes pieces to a blender and purée until smooth, adding some of the steaming liquid to thin the consistency if needed.