Roast potatoes get a shake and very hot fat

For many people, the roast potatoes are the best part of Christmas lunch. In our house there are never enough. Over the years I have stopped trying clever tricks and kept to three simple rules: the right potatoes, a rough shake in the pan, and fat that is properly hot before they go in. I practise in November on ordinary Sundays, so that by December I do not have to think.

The potatoes matter most. I use floury ones, like Maris Piper or King Edward, because their outsides break up and turn crisp, while the inside goes fluffy. Waxy potatoes stay smooth and never get that crunch. For four people I peel about 1.2 kg and cut them into large, even chunks, roughly the size of an egg.

I put them in a big pan of cold, salted water, bring it to the boil and simmer for about eight to ten minutes, until the edges are soft but the middle still has a little resistance when I push in a knife.

Meanwhile the fat goes into the oven. I heat the oven to 220°C, or 200°C for a fan oven, and put a large, heavy roasting tin inside with about four tablespoons of fat. Goose or duck fat gives the best flavour; sunflower or rapeseed oil works well too, and is what I use when vegetarians are coming.

I drain the potatoes in a colander and leave them to steam dry for two or three minutes. Wet potatoes in hot fat spit and never go crisp. Then I tip them back into the empty pan, put the lid on and give them a good shake, so the edges become rough and fluffy. A tablespoon of semolina or flour shaken in with them makes them even crunchier.

This next part is where I am careful. Hot fat is dangerous. I take the roasting tin out of the oven with two oven gloves, put it on the hob, and lower the potatoes in with a large spoon, away from me, turning each one in the fat. I keep the children well away from the oven at this point, and I never add wet potatoes or water to the hot fat.

They roast for 45 minutes to an hour. I turn them once or twice so they colour evenly, and I do not crowd the tin; if they are touching, they steam. Halfway through I sometimes add a few garlic cloves in their skins and a sprig of rosemary.

How dark should they be? The Food Standards Agency advises cooking starchy foods such as potatoes to a golden yellow colour rather than dark brown or burnt, to reduce acrylamide, a chemical that forms when they are cooked at high temperatures. So I aim for deep golden and crisp, not brown, and I leave out the very dark ones.

They are best eaten straight away, sprinkled with flaky salt. Leftovers, if there ever are any, go in the fridge within two hours and get eaten within two days, reheated in a hot oven until piping hot.

On Christmas Day the oven is crowded, so I give the potatoes the top shelf and the hottest part of the oven, and let the turkey rest while they finish.

My roast potatoes that win everyone over, and a hasselback version, are both in the Recipes section of this site, if you would like another way for a different Sunday.

Roast potatoes. Serves 4. About 1 hour 15 minutes. You need 1.2 kg floury potatoes, 4 tbsp goose fat or oil, salt, and rosemary and garlic if you like. Parboil the chunks for 8–10 minutes, drain, steam dry and shake to rough them up. Roast in very hot fat at 220°C (200°C fan) for 45–60 minutes, turning once or twice, until golden and crisp.

How do you make your roast potatoes?