Preheat oven to 450°F. Line a baking sheet with foil
Place each potato between two wooden spoons and carefully make cuts every 1/8-inch without cutting all the way through the potato.
Place the potatoes on the baking sheet and brush them with the melted butter. Season them with salt and pepper.
Bake the potatoes for 55 to 60 minutes or until tender. Remove them from the oven and carefully insert the cheddar cheese slices into each cut in the potato. Sprinkle the tops of the potatoes with the Parmesan cheese then return them to the oven and continue baking until the cheese is melted, about 3 minutes.
Remove the potatoes from the oven, top them with the chopped chives and serve immediately.