Coarsely grate potatoes into a bowl of cold water and let stand 15 – 20 minutes. Meanwhile mix egg and flour until smooth and stir in all remaining ingredients except oil. Drain potatoes, squeeze as dry as possible, and stir into batter. Heat oil in a large, heavy skillet over high heat 1 – 2 minutes. Drop potato mixture by spoonfuls into oil, shaping into 4 or 5 large cakes and flattening slightly with a spatula. Brown 1 – 2 minutes on each side, turn heat down low, and cook pancakes 20 to 25 minutes, turning frequently so they’re cooked through. Drain on paper toweling and serve piping hot.