Tallow roast potatoes

Beef tallow makes the crispest roast potatoes, because it gets hotter than most fats and tastes better too. There are three steps: parboil, rough up the outsides, and roast in smoking-hot fat.

• Serves 6
• Active 20 min
• Total about 1½ hours

Ingredients

• 1.5 kg floury potatoes (Russet or Yukon Gold)
• 100 g beef tallow
• ½ tsp baking soda
• Fine salt, for the water, and flaky salt to finish
• 2 rosemary sprigs and 4 garlic cloves, unpeeled (optional)

Method

1. Heat the oven to 220 °C (425 °F). Put the tallow in a large metal roasting tin and heat it in the oven while you parboil.
2. Peel the potatoes and cut them into 5 cm chunks. Put them in a pan of cold water with a good handful of salt and the baking soda, and bring to the boil. Simmer for 10 minutes, until the edges are soft but the centres are still firm.
3. Drain them and leave them in the colander to steam dry for 5 minutes. Then put them back in the pan, cover, and shake hard until the outsides are fluffy and mashed. The baking soda helps break the surface down. Those rough edges are what go crisp.
4. Take the tin out and carefully tip in the potatoes; the fat should sizzle. Turn them so they're coated all over.
5. Roast for 50–60 minutes, turning them twice, until deep golden and crisp all over. Add the rosemary and garlic for the last 15 minutes.
6. Sprinkle with flaky salt and serve straight away.