Preheat oven to 400°F.
Using a mandoline or sharp knife, cut the neck of the butternut squash into slices an 1/8-inch thick. Arrange them on 2 parchment-lined baking sheets, making sure they don’t overlap. Drizzle with oil or spray with cooking spray, and season with salt and pepper. Bake for 12-14 minutes, or until slightly brown and crispy.