Preheat oven to 425F with the rack in the center.

Thinly slice potatoes to a uniform thickness of ⅛-inch thick. A mandoline makes this job very easy, but you can also use a Chef Knife. Either way, be careful!

For a pretty presentation, try to keep potato slices together to maintain their original shape while tossing them with ¼ cup olive oil and  salt.

Arrange in an overlapping shingled pattern in an 8x8” Baking Dish. They can be arranged in rows or in a swirling pattern, your choice!

Sprinkle with black pepper and sweet paprika and bake 30 minutes.

Strip leaves from thyme sprigs. Add to a small bowl with sage leaves and drizzle with remaining 2 tsp. olive oil and toss to coat.

Remove Baking Dish from oven and top with potatoes with oiled thyme and sage leaves (use the back of a spoon to spread them around) and ½ cup Gruyère.

Return Baking Dish to oven and bake until potatoes are soft and tender on the interior (use a Paring Knife to peel back a few layers to see if the tip can insert easily) and golden brown and crisped on the top, 20–30 minutes more. Top with remaining ¼ cup Gruyère and let cool slightly before serving.