From the Union Square Cafe cookbook. I've made these and they are addictive. These can be made several hours in advance. Store in tightly closed container and reheat at 350 degrees until hot Toss with garlic butter at the last minute.
With mandoline or sharp knife, slice potatoes about 1/16 inch thick. You should have about 6 cups. Place potatoes in large bowl and rinse with cool water until the water runs clear. Thoroughly dry potatoes, first in a salad spinner, then on paper towels. (Any moisture left on potatoes will cause the oil to spatter).
Pour oil into 6-quart heavy bottomed saucepan, 8 to 10" in diameter. The oil should be about 1 1/2 inches deep. Heat the oil to 315 degrees F.
Gently fry the potatoes in two or three batches until light brown and crisp. Stir with slotted spoon to ensure even cooking. Each batch should take 15 minutes to cook. If the potatoes brown faster, the oil is too hot.
As you remove each batch of chips, place them on a cookie sheet lined with paper towels. Place the chips in a large mixing bowl.
Over medium flame heat butter and garlicin a saucepan, without allowing garlic to brown. Drizzle butter mixture over potatoes, add parsley, salt and pepper, and mix thoroughly with a rubber spatula. Serve hot.