Heston’s ultimate roast potatoes

1. Preheat the oven to 180ºC, gas mark 4. Put the potatoes in a colander and hold under running water for 3-5 minutes to wash off the starch, or just until the water runs clear. Drain, place in a large pan, then cover with cold water. Don’t add salt. Bring to the boil, then simmer until very soft and starting to crumble and crack (about 25 minutes). Set a wire rack over a tray. Carefully lift the potatoes from the water using a slotted spoon, and transfer them to the rack. Leave to cool completely; they will firm up. This can be done the day ahead, and then the potatoes covered and chilled overnight, if you prefer.2. Put the beef dripping and olive oil in a roasting tray approx. 35x25cm, large enough to hold all the potatoes in a single layer. Set the tray on the hob (or in the oven for 15 minutes), and let the dripping melt into the oil. Once melted, the fat should come about 0.75-1cm up the sides of the tray. Very carefully place the potatoes in the hot fat. Stir to coat, then place in the oven for 1 hour 30 minutes, gently turning every 20 minutes, until crisp and golden. When you think they’re ready, add another 20 minutes cooking on top, until the potatoes are deeply golden and very crisp. 3. Add the garlic, rosemary and thyme to the potatoes, stir well and cook for a final 5 minutes. Remove the potatoes from the oven, drain on kitchen paper and sprinkle with sea salt to serve. Remove the garlic cloves before eating.