Step 1: Choose potatoes with a dry, flaky texture – Russet/Idaho, Gerla, etc. – that are firm and free from eyes or blemishes. Scrub the unpeeled potatoes under cold running water. Cut them into cubes or chunks, 1½ to 2 inches (3-5 cm). Put them in a saucepan with cold water to cover. Turn heat to high. When the water comes to a boil, reduce the flame to a simmer and cook, uncovered, for 10 minutes. Drain immediately and set aside.
Step 2: Heat olive or sunflower oil to 375ºF (190º C). If you don’t have a thermometer, use the bread cube test.
For the best result you do need to submerge the potatoes completely in oil so they can float freely. Absent a deep fryer, use either a deep frying pan or a heavy gauge saucepan fitted with a wire strainer (or fitted with nothing, so long as you have a slotted spoon). Fry the potatoes without crowding, in small batches if necessary. Once they turn light golden brown, lift them from the oil and drain (on paper towels, unless you’re using a deep fryer, in which case lift the basket, let drain, love the convenience). Just before serving, return the potatoes to the hot oil and fry until deep golden in color. Remove from the oil, drain on paper towels and sprinkle lightly with salt. Serve hot.