Pour around 1 large jug of water, enough to cover the potatoes, sprinkle with rock salt and boil.

When the water comes to boil, plonk the potatoes and switch off the gas.

Drain the water and put the potatoes on a tissue or dry cloth.

Heat the oil till you can see small bubbles on the side. Now add the potatoes, one by one.

Lower the heat to medium and fry till almost cooked but not brown.

Lift the potatoes out of the oil and let the rest of it drain.