Grate the potatoes into the colander, toss with 1 t salt, and set in the sink for 20 minutes.
Squeeze the potatoes with your hands to remove as much liquid as possible, then repeat with the kitchen towel.
Pour the oil into the pan and place over medium high heat. When the oil is shimmery, spread the potatoes in an even layer, pressing down a bit, and sprinkle with the remaining salt and some pepper.
Let fry undisturbed for 5 minutes, then lift up an edge. When it’s golden brown, carefully flip and fry the other side another 5 minutes or so until brown and crunchy.