Place the potatoes in a cheesecloth and wring, extracting as much moisture as possible.
In a medium bowl, stir the potatoes, onion, eggs, flour, and salt together.
In a large heavy-bottomed skillet over medium-high heat, heat the oil until hot. Place large spoonfuls of the potato mixture into the hot oil, pressing down on them with a spatula to form ¼ to ½ inch thick patties. Brown on one side, turn and brown on the other. Let drain on paper towels. Serve hot with applesauce or sour cream.