2
sprigs rosemary + 2 teaspoons minced, for garnish
6
medium baking potatoes, such as russets (6-8 ounce each)
½ teaspoon
sea salt
½ cup
freshly grated parmesan cheese
Method
Preheat the oven to 425°F with a rack in the center position.
Heat the butter, olive oil, shallot, garlic, and rosemary sprigs in a small saucepan over medium-low heat until the butter melts, about 2 minutes.
Peel the potatoes and place them in a bowl of cold water to prevent them from browning.
Slice a very thin layer off one side of each potato. Working one potato at a time, place the potato flat side down. Firmly hold two chopsticks or wooden skewers along the long sides of the potato. Using a sharp knife, thinly slice the potato crosswise until it hits the chopsticks.
Using a fine mesh strainer, strain the butter into a small bowl. Place the sliced potatoes in a 12-inch cast-iron pan or 9x13-inch baking dish. Drizzle the potatoes with half of the butter mixture and sprinkle all over with the salt. Roast until the potatoes are fork tender, 45-50 minutes and beginning to brown.
Remove the potatoes from the oven and drizzle with the remaining butter mixture. Turn on the broiler, then return the potatoes to the oven and broil until the edges are crispy, 5-10 minutes more. Remove the potatoes from the oven and sprinkle with the parmesan. Broil until the cheese is browned, 3-5 minutes more.
Transfer to a serving platter or individual plates. Serve sprinkled with minced rosemary.