Squeeze zucchini with paper towels to remove excess moisture. In large bowl, stir together zucchini, potatoes, onion, flour, egg, salt and pepper until well blended.
In 12-inch skillet, heat 1/4 inch oil over medium-high heat. For each pancake, drop heaping tablespoon of batter into hot oil; flatten slightly. Cook about 2 minutes or until golden brown and edges are bubbly. Turn and cook other side until golden brown. Drain on paper towels. Serve pancakes warm. Garnish with sour cream and chives.