Leftover Mashed Potato Pancakes

Grate 1 ounce Parmesan cheese (about 1/2 cup) and place in a large bowl. Chop until you have 2 tablespoons fresh chives and add to the bowl. Add 1 large egg and lightly beat with a fork or wooden spoon to combine. Add 2 cups cold mashed potatoes and 1/4 cup of the all-purpose flour, and stir to combine. Refrigerate the mixture for 10 minutes.

Place the remaining 1/4 cup flour in a shallow dish. Divide the potato mixture into 8 (1/4-cup) portions. Working with one at a time, shape each portion into a patty about 3-inches in diameter, then dredge the patty in the flour on both sides, shaking off excess. Place on a baking sheet or large plate.

Heat 1 tablespoon of the olive oil in a 10- or 12-inch cast iron or nonstick skillet over medium-high heat until shimmering. Tilt the pan so that the oil coats the bottom. Using a wide, flat spatula, gently transfer 4 of the patties into the pan and cook, flipping once, until golden-brown and crisp, about 3 minutes per side. Repeat with the remaining 1 tablespoon oil and 4 patties. Serve warm with sour cream, if desired.