Heston’s ultimate Christmas roast potatoes

Preheat the oven to 180ºC, gas mark 4. Put the potatoes in a colander and hold under running water to wash off the starch. Drain, place in a large saucepan, then cover with cold water. Add 2 sprigs of rosemary, 6 sprigs of thyme and 2 bashed cloves of garlic. Bring to the boil, then simmer until very soft and starting to crumble (about 25-30 minutes). Drain carefully, then leave to cool in the colander.

Put the beef dripping and olive oil in a roasting tin large enough to hold all the potatoes in a single layer. Put in the oven for 15 minutes (once melted, the fat should come about 0.5cm up the sides). Add the potatoes to the tray with the remaining cloves of garlic. Stir to coat in the oil and place back in the oven for 1 hour, gently turning every 20 minutes.

Meanwhile, make the herb salt. Grind the sea salt flakes, sage leaves, juniper berries, ½ sprig of rosemary leaves and 1 sprig thyme in a spice grinder or pestle and mortar to a fine powder.

After 1 hour, add the remaining rosemary and thyme to the potatoes and return to the oven for a final 20-30 minutes, or until the potatoes are golden brown and crispy. Drain on kitchen paper and season with 4 tsp herb salt before serving.