Step 1

Pull the butter out of the refrigerator to let it soften on the counter. Preheat the oven to 450 degrees Fahrenheit with a rack in the middle of the oven. Line a large, rimmed baking sheet with parchment paper for easy clean-up.

Step 2

To prepare your potatoes, scrub them clean with a vegetable brush under running water. Working with one potato at a time, look for an obvious flat side, then slice a very thin piece off the bottom of the potato to help it rest flat against the cutting board.

Step 3

Place the potato on the cutting board with two chopsticks resting snugly along both long sides of the potato. Starting about ¾ inch from the right (or left, if you’re left-handed), use a sharp chef’s knife to slice as thinly as possible across the potato, ideally ⅛-inch thick slices. It works best to slice at an angle with the tip of the knife on the board rather than straight down. As you cut, you’ll need to readjust your chopsticks so they stay snug against the potatoes. If you accidentally cut a slice out, just tuck it back into its place. Continue slicing to the other end until you’re about ¾” from the tip (use your best judgment).

Step 4

Place your potatoes on the prepared pan. Bake for 1 hour.

Step 5

Meanwhile, in a small bowl, mash the softened butter with the garlic and salt with a fork until evenly mixed. Within the bowl, divide the mixture into two equal portions since we’ll use them at separate times. Set aside.

Step 6

Remove the potatoes from the oven. Work with one-half of the butter and spread a generous amount of butter over the top of each potato. Then use a pastry brush to distribute it evenly over the potato as it melts, gently breaking up any clumps to get in between the layers.

Step 7

Return the potatoes to the oven and bake for 10 more minutes. Remove the potatoes from the oven. Use a butter knife to spread the remaining butter mixture down the center of each potato, letting it melt slowly into the warm potato.

Step 8

Sprinkle all over with flaky sea salt. Add any additional desired toppings, and serve immediately.