Using a sharp knife or mandolin, slice the potatoes to two millimeter thickness.
In a saucepan, melt the butter over medium-heat to a light brown colour, then pour into a bowl.
Grease the bottom of a shallow 13 centimeter ovenproof cast-iron pan with some of the cooked butter.
Cover the bottom of the pan with one-fifth of the potato slices, arranging them in a tiled, overlapping, circular pattern. Brush with one- fifth of the remaining butter and sprinkle with one fifth of the salt. Make four more layers repeating the layering technique, using the remaining potatoes, butter, and salt.
Place the pan over medium heat and cook for five minutes, without disturbing, to initiate browning on the bottom.
Transfer to the oven and bake for 30 minutes, until the potatoes are cooked through and the top is browned.
Remove from the oven and let rest for ten minutes.
Carefully flip the potatoes out of the pan, slice and serve warm, garnish with chives.