Crisp outside, fluffy inside, roast potatoes are a universal favorite. For superlatively flavorful and crunchy roast potatoes, rough up their exterior surfaces and toss them with a small quantity of flour before roasting, use duck fat as the cooking medium, and serve as soon as they are done — if they sit too long, they become soggy.
Grilling potatoes adds a hint of smoky char to their earthy flavor. Tossing the grilled potatoes with garlic and rosemary adds piquancy. The seasonings are added after grilling to keep the flavors fresh — if they are added before cooking, they tend to become harsh and burnt-tasting.
Properly roasted, potatoes produce a crisp and brown crust surrounding a creamy interior. The trick is to cover them during the first part of the cooking, so that the steam cooks the potatoes all the way through, then uncover them so they can acquire a rich brown crust. The garlic and rosemary are added after the potatoes have cooked, rather than before they go into the oven — cooking so long at such a high temperature gives the seasonings an unpleasant bitter taste