Instructions:
- In a large bowl, gently combine the cold mashed potatoes, grated cheese, beaten eggs, flour, chives, garlic powder, pepper, and a light seasoning of salt. Mix only until just combined; overmixing will make the pancakes dense.
- Cover the mixture and chill in the refrigerator for 15–20 minutes. This helps the flour hydrate and prevents the patties from falling apart during frying.
- Divide the mixture into 8–10 equal portions. Lightly flatten each portion into a disc, about 3/4-inch (2cm) thick, ensuring the edges are neat.
- Heat the vegetable oil or butter in a large, heavy-bottomed skillet over medium heat. The oil is ready when a small crumb dropped in sizzles immediately but doesn't smoke violently.
- Carefully place 3–4 pancakes into the hot oil, ensuring they are not touching. Fry undisturbed for 4–6 minutes until the bottom is a deep golden brown and beautifully crisp.
- Gently flip the pancakes using a sturdy spatula. Cook for another 4–5 minutes on the second side until fully golden and heated through.
- Transfer the cooked pancakes immediately to a wire rack set over a baking sheet lined with paper towels to drain off any excess cooking fat.
- Serve piping hot, optionally topped with sour cream and extra chives.