• Position a rack in the center of the oven and heat to 375°F.
• Pile the kale on a large rimmed baking sheet. Toss with the olive oil and vinegar. Sprinkle the lemon zest over the kale and then season very lightly with salt.
• Spread the kale evenly on the baking sheet and roast until it has begun to steam and dry around the edges of the leaves, about 5 minutes. Using tongs, toss the kale, keeping it evenly distributed, and rotate the baking sheet to ensure even cooking. Continue to roast until the kale is dark green and shatteringly crisp, 7 to 10 minutes more. Some of the
  edges may begin to brown. Serve hot or at room temperature soon after roasting.

Tips:

• Wash and dry the kale leaves well in advance of roasting to ensure that they are completely dry.
• Serve these highly snackable chips in a wide, shallow dish, or cool to room temperature in a single layer so they don’t steam and become soggy. Either way, serve soon after roasting.