Special equipment: a salad spinner
Preheat the oven to 325 degrees F. Adjust one oven rack to the upper-middle position and the other oven rack to the lower-middle position.
Remove and discard the ribs from the kale, then slice each leaf in half. In a large bowl, toss the kale with the oil and salt until evenly coated.
Divide the kale among 2 baking sheets, making sure they are in a single layer and not overlapping. Sprinkle the Parmesan cheese over the kale. Set the baking sheets on the oven racks and bake, switching the baking sheets from bottom to top and top to bottom midway through baking, until the kale shrinks in size, about 20 minutes (it may not be completely crispy at this point, but as it cools it will crisp up).
Allow the kale chips to cool completely and crisp up before serving.
Recipe courtesy of Robert Irvine