Place vegetables in a strainer. Rinse with cool water until water runs clear. Drain well. Squeeze out excess water and pat dry with paper towel. Combine grated vegetables with egg, flour , salt and pepper. Heat vegetable oil in large skillet over medium-heat. Working in batches and using 2-3 tablespoons of vegetable mixture per pancake drop mixture into skillet. Flatten slightly and cook until undersides are golden brown. Flip and brown on the other side. Serve with sour cream.