Step 1

Heat oven to 190C/fan 170C/gas Peel the potatoes and cut in half; if very large, cut into quarters, or leave whole if they are small. Tip into a saucepan, cover with cold water, then bring to the boil. Set the timer and boil for exactly 2 mins. Drain the potatoes well, then toss in the colander to fluff up their surfaces, sprinkling over the flour as you go.

Step 2

Place a large, sturdy roasting tray over a fairly high heat, then tip in the fat and oil. When sizzling, lower in the potatoes carefully, then gently brown in the hot fat for about 5 mins so all the sides are covered with oil.

Step 3

Roast undisturbed for 20 mins, then remove from the oven and gently turn them over with a fish slice. Place the tray on the hob to heat the oil, then return to the oven and cook for another 20 mins. Turn again, putting the tray back on the hob to heat the oil. Give them a final 20 mins in the oven, by which time you should have perfect roast potatoes.