Put the mashed potatoes, 2/3 cup of bread crumbs, parmesan cheese and fresh sage in a bowl and mix well. Roll into six balls and then roll the balls in the 2/3 cup of bread crumbs, then flatten out.

Using about half of the olive oil, fry the potatoes, (three at a time) for about two to three minutes on each side or until brown and heated through. Repeat with the other three potato cakes.