Extra-crunchy roast potatoes

Peel the potatoes, if you like, and chop the larger ones into quarters, medium ones in half and leave any small potatoes whole. Tip into a pan of salted cold water and bring to the boil over a high heat, then reduce the heat to a gentle simmer and cook for 15-20 mins until just cooked through. Drain and leave to steam-dry. Will keep chilled for two days.

Heat the oven to 200C/180C fan/gas 6. Drizzle half the oil into a large, shallow roasting tray and heat in the oven for 5 mins. Mix the garlic granules, smoked paprika and the mustard powder together in a small bowl. Lift the tray out of the oven, then tip in the potatoes, sprinkle over the spice mixture and use a spatula to gently turn them in the oil until fully coated. Once cool, will keep covered and frozen for a month. Cook from frozen as per step 3, adding an extra 10 mins. Jiggle the tray to evenly space the potatoes out, drizzle over the remaining oil and roast for 40 mins.

Turn the oven up to 220C/200C fan/gas 8. Gently turn the potatoes over using a spatula, roast for another 15 mins, turn again and roast for a final 15 mins until deeply golden and crunchy. Pile onto a serving plate, season with sea salt and serve straightaway.