Half-fill a large pan with water. Add a large pinch of salt. Pop on a lid and bring to the boil. Preheat your oven to 200°C/Fan 180°C/Gas 6.

Scrub and peel the potatoes. Chop them into roughly equal-sized chunks, around 3-4cm across. Pop them in a large colander and rinse under cold water to get rid of some of the starch. When the water in the pan is boiling, add the potatoes. Bring back to a gentle simmer, and then simmer for 5 mins.

Drain the potatoes, then tip back into the pan. Gently shake to rough up the edges. Lay a couple of clean tea towels on your kitchen surface. Tip the potatoes onto them. Spread them out. Let them steam-dry for 5-10 mins.

Meanwhile, add 4 tbsp oil to a large roasting tin (or 2 medium tins). Put them in the oven to heat the oil for 10 mins.

Take the roasting tin out of the oven. Add the spuds. Season with a pinch of salt. Turn them a few times to coat in the hot oil. Make sure the potatoes aren’t too crowded. Roast for 45 mins, turning the potatoes after 20 mins, till they’re golden brown.

While the potatoes roast, pick the rosemary leaves off the woody sprigs. Peel and thinly slice 4 garlic cloves. After 45 mins, remove the tin from the oven and scatter over the rosemary and garlic. Turn the potatoes a few times. Return to the oven for 5-10 mins till golden brown and crisp. Transfer to a dish and serve.