3 medium-to-large firm (unpeeled) pears, any variety, stemmed
Preheat the oven to 225 degrees. Line 2 baking sheets with parchment paper.
Use a chef’s knife or a mandoline to slowly slice the pears very thinly lengthwise, discarding (or eating) the very end slices. Include slices that have some core, but first cut out the seeds and the tough center part.
Arrange the slices in a single layer on the baking sheets; bake for 11/2 hours, then use tongs to turn the slices over. Bake until the pears are dried and slightly darkened and the edges have curled, 1 to 11/2 hours more (for a total of 21/2 to 3 hours). They will still be pliable when they are done but will crisp further as they cool.
Allow to cool completely on a wire rack before serving or storing.
Per serving: Calories 100; Protein 0g; Total carbohydrates 24g; Total Fat 0g (Saturated fat 0g); Cholesterol 0mg; Sodium 0mg; Dietary fiber 5g