Peel and coarsely shred the potatoes. (Place in cold water as you work to prevent darkening.) Rinse potatoes and drain well. Pat dry with paper towels.
In a large mixing bowl combine egg, flour, salt and pepper until smooth. Stir in potatoes and onion until vegetables are coated with egg mixture.
In a 12-inch skillet heat 1/2-inch cooking oil over medium-high heat. For each latke, drop 1 rounded tablespoon potato mixture into hot oil, flattening slightly. Fry for 2 to 3 minutes or until edges are crisp. Turn and cook for 2 to 3 minutes more or until golden.
Drain on paper towels. Cover with foil and keep warm. Repeat frying.
For make ahead latkes: Prepare, cook and drain latkes. Cover and chill up to 24 hours in the refrigerator. To reheat, arrange on an ungreased baking sheet. Bake, uncovered, in a 400-degree oven for 10 to 12 minutes or until heated through, turning once.