Step 1

Preheat oven to 400°F (207°C).

Step 2

Using a Mandoline Slicer, thinly slice the peeled potatoes length ways. Pat dry the potatoes with paper towels.

Step 3

Place the sliced potatoes in a large bowl. Using your hands, toss with butter (or duck fat), 2 teaspoons salt, black pepper and about 2 teaspoons of chopped rosemary until fully coated.

Step 4

Carefully place the potatoes upright, from left to right, in a baking tray (I used a 8x11" baking tray) until the tray is full. Do not pack in the potatoes too tightly, as this impacts the crispiness.

Step 5

Bake for an hour, or until the potatoes are golden and crispy. Garnish with the remaining salt and the rosemary or oregano. Serve immediately.