Roast potatoes are a staple side dish for many dinners, but especially a roast dinner where they accompany the meat beautifully.

They can be made in a variety of different ways, but Mary Berry’s recipe uses the addition of one ingredient to ensure a crunch.

The recipe notes said: "A roast potato should be ultra crispy and golden on the outside with fluffy light middle.

"Par-boiling and roughing them up before roasting gives a lovely crunchy exterior, and the semolina adds an extra crunchy coating."

This recipe serves six people and cooks in under one hour. They can be prepared up to 12 hours in advance too, by part-roasting them for 35 minutes, then roasting again for 20 minutes when they are ready to be eaten.

Ingredients:

1.5kg of old potatoes, peeled and cut into medium-sized cubes

40g of semolina

Four tablespoons of goose fat or vegetable oil

Three thyme sprigs

Salt

Method:

Start by preheating the oven to 220C or 200C fan before putting the potatoes in a saucepan of cold salted water.

Bring the water to a boil and let the potatoes boil for just five minutes until starting to soften around the edges.

Drain them into a colander until completely dry, then place them back into the saucepan and shake again to roughen up the edges.

Doing so will help to achieve a crispy exterior, as well as the semolina, which should be added at this stage.

Preheat a large shallow roasting tin in the oven until hot before adding the fat to the dish and heating for five minutes until it begins to smoke.

Carefully add the potatoes, before turning them in the fat until coated and then scatter in the thyme sprigs.

Return the dish to the oven and roast for around 45 to 55 minutes until golden brown and crispy.

Make sure to turn the potatoes halfway through cooking to ensure even coating before serving them with your chosen dinner.