Slice potatoes thinly and remove excess moisture.
Preheat oven to 400℉.
Preheat the cast iron skillet with 2 tbsp of olive oil.
Add the melted butter to the potatoes with salt and pepper.
Start layering your potatoes on the cast iron, starting from the center.After each layer put some cheese, then more potatoes. Repeat for about 6-7 layers. Make sure the last layer is potatoes and not cheese.
Cover the top of the potatoes with parchment paper and add something heavy, lLike a skillet or pot.
Cook on the stove at medium high for about 7-8 min.
Remove the parchment paper and bake at 400℉ for 55 min.
Place the parchment on top of the potatoes again, flip it onto a cutting board. Cut into triangles and transfer to a plate.
You can add flaky sea salt, pepper, and chives on top.