Preheat the oven at 375º. In a large pan place the potatoes and cover with water. Add sea salt and cook until the potatoes are resisting a bit when knife inserted to feel doneness.
Spread evenly the butter in a gratin dish. Drain the potatoes and place half on the gratin dish. Sprinkle with salt and pepper; add the desired amount of cheese to it. Cover with the remaining potatoes, sprinkle with salt and pepper. Add the cream cheese and place in the hot oven for 30 minutes or until golden brown.