Duck Fat Potatoes

Method

Parboil and rough up

1. Peel the potatoes and cut into 7.5 cm (3 inch) pieces: halve medium potatoes and cut large ones into three.
2. Preheat the oven to 230°C (230°C fan / 450°F / gas 8).
3. Bring a large pot of chicken stock to the boil. Add the 1 tbsp salt, then the potatoes, and boil for 10 minutes.
4. Drain the potatoes well. Shake the excess liquid out of the pot and return it to the turned-off stove. Tip the potatoes back in and let them stand for 5 minutes to steam dry.
5. Add the 1½ tsp salt and the MSG, put the lid on and shake the pot up and down vigorously 5–7 times to rough up the surfaces.

Roast

1. Put the duck fat in a heavy metal roasting pan (not glass or ceramic) and heat in the oven for 5–7 minutes, until shimmering and very hot with little wisps of smoke. A pinch of potato should sizzle vigorously.
2. Working quickly and carefully, take the pan out, add the potatoes and turn to coat in the fat, then arrange them cut side down.
3. Roast for 25 minutes. Turn the potatoes and roast for 15 minutes, then turn again and roast for 10–15 minutes more, until deep golden and very crunchy.
4. Transfer to a warm bowl, sprinkle with sea salt flakes and rosemary and serve immediately.