Half-fill a large pan with water. Add a pinch of salt. Cover and put on a high heat to come to the boil. Meanwhile, scrub and peel the potatoes (see our tip on how to make the most of your veg peelings). Chop the potatoes into 3-4cm-thick chunks. When the water is boiling, add the potatoes. Turn the heat down to a simmer. Cook the spuds for 5-6 mins.

Heat your oven to 200°C/Fan 180°C/ Gas 6. Add43 tbsp oil to a large roasting tin. Pop in the oven for 10 mins to heat the oil. Use two smaller tins if you think that will the potatoes more room to roast. If the tins are too crowded the potatoes will steam rather than roast.

Drain the potatoes. Tip them back into the pan. Put the lid on the pan. Shake gently a few times to rough the edges of the potatoes (be careful not to break them up too much). Lay a couple of clean tea towels on your kitchen surface. Tip the potatoes onto them. Spread the potatoes out. Let them steam-dry for up to 10 mins (no longer than that or they will develop a ‘skin’ and become leathery).

Take the roasting tin out of the oven. Add the potatoes. Season with a pinch of salt and pepper. Turn the spuds a few times to coat them in the hot oil. Slide into the oven and roast for 40 mins, till golden brown. Turn the potatoes over in the oil after 20 mins. If you’re using two tins, swap them over halfway through cooking.

While the potatoes roast, finely chop the rosemary leaves. Peel and finely slice the garlic cloves. Take the potatoes out of the oven and add the garlic and rosemary to the tin. Turn to mix the potatoes and herbs together. Roast for a further 5-10 mins, till the potatoes are golden and the garlic is crisp.

Tip the potatoes into a serving dish and serve straight away.