Crispy Roast Potatoes

• 1.2kg floury potatoes (Maris Piper or Russet), peeled, in large chunks
• 1 tbsp salt, for the water
• ½ tsp bicarbonate of soda
• 80ml duck fat, goose fat or olive oil
• 4 garlic cloves, unpeeled and smashed
• A few rosemary sprigs
• Flaky sea salt

Heat the oven to 220°C (200°C fan) with the fat in a large roasting tin.

Boil the potatoes in water with the salt and bicarb until the edges are soft.

Drain and leave to steam dry, then shake hard in the colander to rough up the edges.

Carefully tip the potatoes into the hot fat, turn them to coat and roast.

Turn them, add the garlic and rosemary, and roast until deep golden and crisp.

Sprinkle with flaky salt and serve straight away.