Ingredients
Kosher salt
1/2 teaspoon (4g) baking soda
4 pounds (about 2kg) russet or Yukon Gold potatoes, peeled and cut into quarters, sixths, or eighths, depending on size (see note)
5 tablespoons (75ml) extra-virgin olive oil, duck fat, goose fat, or beef fat
Small handful picked rosemary leaves, finely chopped
3 medium cloves garlic, minced
Freshly ground black pepper
Small handful fresh parsley leaves, minced
Directions
1.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.
2.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 oil through a fine-mesh strainer set in a large bowl. Set garlic/rosemary mixture aside and reserve separately.