Twice-Baked Potatoes

Rub russets with oil and salt and bake them at 200°C until a skewer slides in, about an hour. Cut off the top third and scoop the inside into a bowl, leaving a 5 mm wall so the skins hold their shape. Mash the potato with butter, sour cream, cheddar, chives and salt. Pile it back in, top with more cheese, and bake 15 to 20 minutes until the top browns. You can fill them a day ahead and keep them in the fridge, which makes them good for a steak night.