Makes 10 servings
5 pounds (2.25 kg) Yukon Gold potatoes
½ cup (120 g) unsalted butter (at room temperature)
1 whole nutmeg, for grating
7 ounces (200 g) Red Leicester cheese, or other sharp cheddar
Peel the potatoes, cutting up any larger ones so that they’re all a similar size, then cook in a large pan of boiling salted water for 15-20 minutes, or until cooked through. Drain in a colander and leave to steam dry, then return to the pan and mash well. Mix in ¼ cup of butter and the milk; finely grate in half of the nutmeg, the taste and season with salt and pepper.
In a round or rectangular baking dish, lightly grease with the remaining butter. Coarsely grate in enough cheese to fill the bottom of the dish. Spoon in the mash, randomly adding little dollops of the remaining cheese as you to, which will melt as it bakes adding a nice surprise. Dot the remaining butter over the dish and lightly drizzle with olive oil.
Can be baked immediately, or can be kept in the refrigerator for later.
Bake for 35 minutes, or until golden and crispy on top.