Preheat the oven to 425 degrees F. Peel the potatoes if the skin is too tough, otherwise just scrub and rinse them.
Cut the potatoes into thin slices (but not all the way through – place the handle of a spoon or table knife alongside the potato to prevent the knife from slicing all the way).
Put the potatoes in a baking dish; slightly fan out the slices.
Drizzle the potatoes with melted butter and sprinkle with herbs and salt (to taste).
Bake the potatoes for about 50 minutes.Remove the potatoes from the oven, sprinkle with parmesan and cheddar cheese.
Bake the potatoes for another 10-15 minutes (until they’re lightly browned and soft inside, and the cheeses are melted).