Step 1

Preheat the oven to 425°F

Step 2

In a small sauce pan over medium-low heat melt the butter with the olive oil, shallot, garlic and rosemary

Step 3

Set aside.Peel the potatoes and place them in a bowl of cold water, to prevent them from turning brown.Slice a very thin layer off the bottom of each potato so that they don’t roll while slicing them

Step 4

With the flat side of the potato down, place 2 chopsticks or wooden skewers on either side and firmly against the body of the potato (lengthwise)

Step 5

Using a sharp knife, thinly slice the potato pressing knife down until it hits the wooden skewer

Step 6

Be careful on the edges of the potato, not to trim the sides off unintentionally.Place sliced potatoes back into the cold water

Step 7

Using a fine mesh sieve, strain the butter into a bowl

Step 8

Once all the potatoes are all sliced, place in a 12 inch cast iron pan or 9x13 baking dish

Step 9

Drizzle potatoes with ½ of the butter mixture

Step 10

Sprinkle with salt.Bake in the oven, on middle rack, for 45-50 minutes, until tender when pierced with a fork in the center

Step 11

This may be a few minutes more or less, based on your oven and the size of your potatoes

Step 12

Remove from the oven and drizzle with the remaining butter mixture broil for 5-10 minutes until edges are crispy

Step 13

Sprinkle parmesan cheese evenly over the potatoes

Step 14

Place the potatoes back into the oven for 3-5 minutes longer until the cheese is nicely browned.