Start salted water boiling. Once at a rolling boil add potato cubes. Cook until fork tender.
Drain potatoes and add to large mixing bowl. Mash slightly, then add cornstarch, butter, heavy cream, salt, pepper and 2 tablespoons of parsley. Allow to cool for about 10 minutes.
Use a food scoop to portion out the mashed potatoes into spheres. Gently roll between gloved palms to smooth out the edges.
Bring about 1 inch of oil to 350degF. Gently add the formed balls in batches to the hot oil. Fry until golden brown. Remove to a wire rack to cool and sprinkle with remaining parsley before serving with your favorite fry sauce.