Boil the potatoes until tender; peel and mash them. Stir in the walnuts, parsley, salt, pepper to taste, and eggs, mixing well.
In a 10-inch skillet with sloping sides, melt 1 tablespoon each of butter and oil. When hot, spoon the pancake batter into the pan, pressing down with a spatula to form an even cake. Cook over medium high heat for about 4 minutes, or until the bottom of the pan