1. Preheat oven to 400°.
2. Set mandoline on thinnest slicing setting. Cut each potato lengthwise into 28 slices using mandoline. Arrange potato slices in a single layer on several layers of paper towels; cover with additional paper towels, and press lightly. Let stand 5 minutes.
3. Arrange 14 potato slices in a single layer on each of 2 baking sheets coated with cooking spray. Place a small herb sprig on each potato slice; cover with another potato slice. Press gently to adhere. Coat potato stacks with cooking spray. Sprinkle evenly with salt. Working with one sheet at a time, cover potato stacks with parchment paper. Place an empty baking sheet on top of parchment paper; set a cast-iron or heavy ovenproof skillet on second baking sheet. Bake at 400° for 25 minutes.
4. Remove skillet. Remove baking sheets from oven; remove top baking sheet and parchment paper. Remove browned potato chips from pan; place on a wire rack. Turn any unbrowned potato chips over on sheet. Replace parchment paper and top baking sheet; return pan to oven. Replace skillet on top of baking sheet. Bake 5 minutes or until browned. Cool chips on wire racks. Repeat procedure with remaining potatoes. Store chips in an airtight container up to 2 days.