Adapted from kqed.org
Preheat the oven to 400F. Have ready a heavy roasting pan that will hold the potatoes in an even layer.
Peel the potatoes and cut them into quarters so they are all about the same size; they should be roughly 2–3 inch chunks. Place the potatoes in a large saucepan and add enough cold water to cover them. Season with plenty of salt and bring to a boil over high heat. Once they boil, stir, reduce the heat to medium, and simmer for 5 minutes.
While the potatoes cook, add the oil to the roasting pan and place the roasting pan in the oven to heat.
Using the lid, carefully drain the water from the pan. Cover the pan and give it a good shake to bash up the potatoes slightly. This creates a rough surface all over the potatoes which helps them crisp in the hot fat. Remove the lid and set the pan aside, uncovered, for the potatoes to dry for a few minutes.
Carefully (seriously, water hitting hot oil splatters!) add the potatoes to the hot oil in a single layer so they are not touching and return the pan to the oven. Roast, turning them about every 15 minutes or so, until they are deeply golden brown and crisp and tender throughout, 60–75 minutes. Serve while hot.