Adjust oven rack to lowest position, place rimmed baking sheet on rack and heat oven to 450 degrees.

Place cut potatoes and 1 tablespoon of kosher salt in large Dutch oven; cover with cold water by 1 inch. Bring to a boil over high heat; reduce heat and gently simmer until exteriors of potatoes have softened but centers offer resistance when pierced with paring knife, about 5 minutes.

Drain potatoes and transfer to large bowl. Drizzle with 2 Tablespoons of olive oil and 1/2 teaspoon salt; using a rubber spatula, toss to combine. Drizzle with another Tablespoons oil and 1/2 teaspoon salt; continue to toss until exteriors of potatoes are roughed up, about 1 to 2 minutes.

Remove baking sheet from oven and coat with 1 tablespoon oil. Transfer potatoes to baking sheet and spread into an even layer, skin side up if end pieces.

Bake until bottoms of potatoes are golden brown and crisp, 15 to 25 minutes.

Remove baking sheet from oven and using a metal spatula, loosen potatoes and flip each slice over. Continue to roast until second side is golden and crisp, 10 to 20 minutes longer. Season with more salt and pepper. Serve immediately.