Crisp Hash Browns

Pour the litre of cold water into a large bowl.

Grate the potatoes on the coarse holes of a box grater straight into the water, so the shreds cannot brown while you work.

Swirl them hard with your hand until the water turns chalky white.

Drain the shreds in a sieve set over a second bowl, keeping the cloudy water underneath.

Stand that water for 5 minutes, until a dense white layer of starch has settled on the bottom of the bowl.

Pour the clear liquid off carefully and keep the settled starch behind.

Tip the drained shreds onto a clean tea towel, in two batches if the towel will not take them all.

Gather the corners and wring the towel out over the sink until nothing more runs, considerably harder and for longer than feels reasonable.

Treat the wringing as the recipe. Any water left in the shreds has to boil off before the potato can fry, and a wet mixture steams itself soft and grey in the pan and never crisps at all.

Put the wrung potato in a dry bowl and scrape the reserved starch in on top of it.

Toss it through with the fine salt and the ground peppercorns.

Season at the last minute rather than in advance. Salt pulls water straight back out of raw potato, and a bowl left standing for ten minutes is wet again.

Divide the mixture into 8 and press each portion into a patty about 1.5cm thick, squeezing it tight so it holds its shape.

Heat the oil in a wide heavy frying pan over medium heat until it shimmers.

Lay in as many patties as fit with a couple of centimetres between them, flattening each once with a fish slice.

Cook for 4-5 minutes without touching them, until the visible edge has gone deep gold and lacy.

Leave them alone for the whole of that time. The crust has to set before it can carry the patty, and one turned early tears and leaves half of itself welded to the pan.

Turn each patty over.

Drop the butter into the pan and let it foam around them.

Cook for a further 3-4 minutes, spooning the butter over once or twice, until the second side matches the first and the middle feels firm under the slice.

Keep the butter back until this point. It burns long before the potato is cooked if it goes in at the start, and burnt milk solids taste bitter right through the crust.

Lift them onto kitchen paper for a few seconds.

Fry the second batch the same way, in the fat left in the pan.

Finish with flaky salt while they are still glossy.

Serve straight away, since the crust starts softening the moment they leave the pan.