2 pounds Yukon Gold potatoes – peeled and cut into 2-inch chunks
3 quarts water – for boiling
2.5 tsp kosher salt
4 tbsp olive oil
3 cloves garlic cloves – lightly crushed
2 sprigs fresh rosemary sprigs
0.5 tsp black pepper – freshly ground
Instructions
Preheat the oven to 450°F (230°C). Set a large rimmed baking sheet on the middle rack to heat, 10 minutes.
Peel the potatoes and cut into 2-inch chunks, then rinse briefly to remove surface starch, about 30 seconds.
Put the potatoes, water, and 2 tsp of the kosher salt in a large pot. Bring to a boil over high heat, then reduce to a simmer and cook until the edges are just tender and the surfaces look slightly rough, 8–10 minutes.
Drain well, return the potatoes to the empty pot, and let steam-dry, 2 minutes. Shake the pot to rough up the surfaces, 10–15 seconds.
While the potatoes are draining, pour the olive oil onto the hot baking sheet and heat until the oil is shimmering, 5 minutes.
Carefully add the roughened potatoes to the hot oiled sheet, turning to coat and spacing them in a single layer. Roast until the bottoms are golden, about 20 minutes.
Flip the potatoes. Scatter the garlic cloves and rosemary sprigs onto the pan and continue roasting until deeply golden and crisp, 15–20 minutes.
Sprinkle the remaining 0.5 tsp kosher salt and the black pepper over the potatoes and toss briefly on the sheet. Serve hot, discarding the rosemary and garlic if desired.