Rinse and scrub the potatoes. Fill a large pot with water and add a few pinches of kosher salt. Bring to a boil, then boil the potatoes for about 20 minutes until tender (test one with a fork to see if it slides through easily). Drain the potatoes and run them under cold water. Slip the skins off of the potatoes (if desired; it takes a bit of time but makes for a polished look), and cut them into bite sized pieces.
In a small bowl, mix together sour cream, olive oil, lemon juice, and the kosher salt. Pour the dressing over the potatoes and add plenty of fresh ground black pepper. Mix to combine, and add additional kosher salt to taste. Serve immediately at room temperature. For leftovers, allow the salad come to room temperature and add a bit more fresh lemon juice and kosher salt prior to serving.