Using a food processor or a box grater, grate the potato and onion on the large hole into a bowl. Using your hands, squeeze out the excess liquid and place the dry potato onion mixture in a bowl. Add the egg, parsley, flour, breadcrumbs, thyme, lemon juice and seasonings. Mix well. Heat 1/2 cup of oil in a heavy skillet. Add 1/2 cup mounds of potato mixture to the hot oil, and flatten down to a 3/4-inch thick pancake. Turn heat to medium. Cook for 5 minutes on each side, or until crispy and golden. Serve with the applesauce.