Step 1

Scrub the potatoes clean and place in a large saucepan. Add enough cold water to cover potatoes by about an inch. Stir in 2 tablespoons of the kosher salt, place over high heat, and bring to a boil. Reduce the heat and simmer until the potatoes are very tender and can be easily pierced with a sharp knife with no resistance, 20 to 25 minutes. Drain and set aside.

Step 2

Add enough cold water to cover potatoes by about an inch. Stir in 2 tablespoons of the kosher salt, place over high heat, and bring to a boil.

Step 3

Reduce the heat and simmer until the potatoes are very tender and can be easily pierced with a sharp knife with no resistance, 20 to 25 minutes. Drain and set aside.

Step 4

Arrange 2 racks to divide the oven into thirds and heat to 500°F. Place the butter in the now-empty pot and melt over low heat. Remove from heat and stir in the garlic, parsley, pepper, and remaining 3/4 teaspoon kosher salt.

Step 5

Add the potatoes and toss to coat.

Step 6

Pour the potatoes and any extra melted butter mixture onto a rimmed baking sheet. Using the bottom of a lightly greased drinking glass or measuring cup, press down on each potato until it splits open and is flattened to 3/4-inch thick.

Step 7

Roast on the lower rack until the bottoms are golden-brown, about 10 minutes. Move to the higher rack and roast until the tops are brown and crispy, 10 to 15 minutes more. Serve warm.