Position a rack in the center of the oven and preheat the oven to 375°F. Line a cookie sheet with parchment paper

Peel the potatoes and rinse them under cold running water. (If you wish to leave the skin on, for a healthier component, make sure you scrub the potatoes well before use.) Using a chef’s knife or a mandoline, slice the potatoes lengthwise into .-inch-thick planks. Place them in a baking pan and pour the buttermilk over them to soak a bit and also to prevent them from discoloring.

Thoroughly mix together the bread crumbs, basil, oregano, rosemary, red pepper flakes, and salt in a medium-size bowl. Place a potato plank, still coated with buttermilk, in the seasoned crumbs, making sure it gets well cloaked. Place this on the prepared cookie sheet. Repeat, using up all the potato planks and crumbs. If you pack the planks close together, you should be able to fit them all on 1 cookie sheet. Wash and dry the baking pan and set aside.`

Liberally drizzle olive oil over the planks—don’t skimp on oil. It is essential not only to provide good flavor, but also to turn the slices crispy brown. Place the cookie sheet in the oven and roast the planks, flipping them periodically to ensure even browning, until they are crispy all over and tender when pierced through the crackly shell with a fork or knife, about 45 minutes. Remove the cookie sheet from the oven

Cover the bottom of the baking pan with about 1 1⁄3 cups of the sauce. Place a layer of the crisped potato planks on the sauce and top them with another 11⁄3 cups of the sauce. Spread half the mozzarella slices over the sauce, followed by another layer of the baked potato planks. Spread the remaining sauce over this layer. Cover the baking pan with aluminum foil and bake until the sauce is bubbly, about 30 minutes.

Remove the foil and sprinkle the Parmigiano-Reggiano evenly over the sauce, followed by the remaining mozzarella slices. Return the pan to the oven, uncovered, to melt the cheesy topping, about 5 minutes

Remove from the oven, sprinkle with the fresh basil, and serve.