1In medium bowl, mix all ingredients except oil, sour cream and additional green onions until blended.
2In 12-inch skillet, heat 2 tablespoons of the oil over medium-high heat. Scoop sweet potato mixture by 1/4 cupfuls into skillet; flatten slightly. Cook 4 minutes or until golden brown, turning once. Drain on paper towels. Repeat with remaining batter. Add remaining oil as needed to prevent sticking. Top with sour cream. Garnish with additional green onions.