Place potato chunks into a large pot and cover with cold water. Add 1 tsp salt the water. Bring the potatoes to a boil, then lower to medium high cooking for 10-12 minutes or until fork tender. Drain well and then return to pot.
Unwrap cheese wedges. Add to the hot potatoes along with the sour cream, butter and reserved 1 tsp salt. adjust to taste, adding black pepper, if desired.
Using an electric mixer whip the ingredients together, slowly adding warm milk. Continue to whip until the potatoes are smooth and creamy. Add slowly until they reach your desired consistency.
Taste and adjust salt to your taste. Add 3/4 cup shredded Swiss mixing in by hand.
Serve hot with a pat of butter and a sprinkle of reserved shredded Swiss cheese and parsley on top.