Peel potatoes and then grate them. Place grated potatoes into a bowl filled with water. Grate onion and also place into a bowl with the potatoes. Soak the potatoes for about 5 minutes or so. Mix together flour and egg in a large bowl until well blended. Season flour mixture with black pepper and salt. Drain water from potatoes and squeeze potatoes dry with your hands.
Stir together flour mixture and potatoes until you have a uniform consistency. Heat a skillet to 350 degrees add a couple of teaspoons of oil. Make pancakes by taking about 1/4 cup of potato pancake mix and patting it out into the pan, cook until browned on one side, flip over, and then brown on the other side. This should take 4 to 5 minutes on each side. Serve with sour cream and applesauce.