Combine all potatoes with onion, flour, eggs, chives, salt and paprika.
Transfer mixture to large colander set over large bowl. Form 1/4 cupfuls of mixture into 3" wide patties blot with paper towels.
In nonstick skillet, heat 2 Tbsp. oil over medium high heat. Add patties, in batches. Cook, turning once, and adding more oil as needed, until golden, 4-5 minutes per side. Drain on paper towels. Serve warm with sour cream.