Appleasuce, sour cream or Greek yogurt, or garnish
Using a food processor or box grater, grate the potatoes (no need to peel them). Using a clean tea towel or cheesecloth, squeeze out potato liquid, getting the shreds as dry as possible. Add potatoes to a very large bowl, and mix together with chopped onion, egg, flour, salt and pepper.
In a large cast-iron skillet (or other heavy bottomed skillet), heat a half-inch of oil over moderate heat. Add heaped tablespoons of latke mixture, frying four or five at a time, for about three minutes on each side (smoosh them down with the spatula a bit), or until golden brown. Add more oil as needed.
Drain on paper towels and serve immediately, or cook ahead and reheat when guests arrive. Don’t forget the applesauce!