The Best Crispy Roast Potatoes Ever

Adjust oven rack to center position and preheat oven to 450°F (230°C) (or 400°F (200°C) if using convection).

Heat 2 quarts (2L) water in a large pot over high heat until boiling.

Add 2 tablespoons kosher salt (about 1 ounce; 25g), baking soda, and potatoes and stir.

Return to a boil, reduce to a simmer, and cook until a knife meets little resistance when inserted into a potato chunk, about 10 minutes after returning to a boil.

Meanwhile, combine olive oil, duck fat, or beef fat with rosemary, garlic, and a few grinds of black pepper in a small saucepan and heat over medium heat. Cook, stirring and shaking pan constantly, until garlic just begins to turn golden, about 3 minutes.

Immediately strain the oil through a fine-mesh strainer set in a large bowl. Set the garlic/rosemary mixture aside and reserve them separately.

When the potatoes are cooked, drain them carefully and let them rest in the pot for about 30 seconds to allow excess moisture to evaporate.

Transfer to the bowl with the infused oil. Season to taste with a little more salt and pepper, and toss to coat, shaking the bowl roughly, until a thick layer of mashed potato–like paste has built up on the potato chunks.

Transfer the potatoes to a large rimmed baking sheet and separate them, spreading them out evenly. Transfer to oven and roast, without moving, for 20 minutes.

Using a thin, flexible metal spatula to release any stuck potatoes, shake pan and turn potatoes. Continue roasting until the potatoes are deep brown and crisp all over, turning and shaking them a few times during cooking, 30 to 40 minutes longer.

Transfer the potatoes to a large bowl and add the garlic/rosemary mixture and minced parsley. Toss to coat and season with more salt and pepper to taste. Serve immediately.