Mashed Potato Pancakes

Combine mashed potatoes, breadcrumbs, cheese, onion powder, pepper and 2 tablespoons chives in a medium bowl; mix well. Divide the mixture into 4 balls (about 1/2 cup each). Flatten the balls into 3-inch-diameter cakes, about 1/2 inch thick.

Heat oil in a large cast-iron or stainless-steel skillet over medium heat until shimmering. Add the potato cakes; cook, undisturbed, until golden brown, about 5 minutes per side. Transfer to a platter. Sprinkle with the remaining 1 tablespoon chives. Serve with sour cream.