In a small bowl combine sour cream and cilantro; season to taste with salt and pepper. Set aside.
In a deep skillet heat about 1/2-inch oil over medium heat to 360 degrees F. Using a mandoline or ridged slicer on a box grater, cut potato into 1/8 to 1/4-inch thick waffled slices. Do not rinse. If moist pat off excess moisture from slices with paper towels. Fry potato slices, a few at a time, turning once or twice, until tender and golden. Remove with a slotted spoon to drain on paper towels; season with salt and pepper.
To serve, dab some sour cream mixture on a pretty plate and top with a potato slice. Build a tower, alternating potato slices and sour cream mixture, to desired height. Use a truffle slicer or other shaving device to shave truffles on top.
Yield: 2 to 4 servings as a first course