Kartoffelsuppe Mit Sahne (Potato Soup w Cream)

4 cups peeled and diced raw potatoes;
1 small onion, sliced or diced;
1/2 cup cream;
2 tablespoons butter;
1/4th teaspoon pepper;
1 teaspoon salt

Cover potatoes and onion with unsalted water and boil
until well done, adding more water as needed.
Add the cream, butter, salt and pepper. Let boil and
serve hot.

Serves 4 to 6