Roast potatoes are at their best fresh out the oven, in stark contrast to many restaurant or buffet potatoes, which start to sweat and soften after resting too long. Choosing an appropriate potato variety is significant, as is roughing up the spuds’ surface prior to roasting.
Pick a Potato
Not all potatoes are suitable for roasting. High-starch varieties, in particular, fall apart too easily during parboiling and can dry out in the oven rather than fluffing up. Use either an all-purpose potato such as a yellow Finn or Yukon gold, or a waxier variety such as a red bliss for skin-on wedge-style roast potatoes. Wash and peel the potatoes -- don’t peel wedges, though -- and cut them into even-sized quarters if using medium-size potatoes. For larger potatoes, cut even-sized cubes of at least 1 inch. Keeping the size of the potato pieces regular allows for more consistent doneness. Submerge peeled potatoes in cold water if making a big batch to keep the surface from discoloring.
Parboil potatoes before roasting. Place enough lard or duck fat in a baking tray to form a thin film over the base when melted -- although a layer of olive oil will do -- and slide into an oven preheated to 425 degrees Fahrenheit. Meanwhile, place the cut potatoes into a pot, cover with salted water and bring to a boil, simmering for about 7 minutes. The inside should still be firm with the outside soft enough that the tines of a fork create furrows when dragged across. Drain the water through a colander and allow the potatoes to steam dry for up to 3 minutes. Shaking the potatoes gently is a crucial step that roughens the exterior texture to enhance crispiness during roasting.
Roast and Season
Carefully remove the baking tray from the oven and transfer the potatoes to the tray in a single layer. Roll the tray around to baste the potatoes with the hot fat. Place the tray on the highest shelf of the oven and roast for 40 to 50 minutes until the potatoes are golden brown, flipping them half way through for even browning. For maximum crispiness, roast the potatoes for 30 minutes then squash each one down slightly with a potato masher. Season the tray with more butter, herbs or flavors such as citrus zest, and return to the oven for 30 minutes.
For wedge-style potatoes, leave the skin on and drizzle the potatoes with olive oil and kosher salt after parboiling. Laid flat on a baking tray, the potatoes should be brown and crispy after 40 minutes in a 450-degree F oven.
Tips and Serving Suggestions
Sprinkling the potatoes with flour after parboiling and draining enhances the texture of their surface, but roughing them up in the colander is usually sufficient. Above all, do not overboil them or they will lose structure, but don’t be afraid either to roast them beyond standard tenderness. As the outside becomes crispy, the moisture is sealed in for a fluffy interior with the consistency of mashed potato. To test for doneness, poke a potato with a fork. It should easily penetrate to the center of a cooked potato.
Kosher salt and pepper come as a standard seasoning, but any fragrant herb, such as rosemary sprigs, thyme or marjoram scattered over the baking tray provides a pleasant complementary aroma. Crushing some garlic cloves and sowing them among the potatoes also infuses the final dish with intoxicating flavors.