01 - In a large mixing bowl, combine cold mashed potatoes, shredded cheddar cheese, finely chopped green onions, garlic powder, black pepper, salt, and 1 large egg. Mix thoroughly until uniform.
02 - Portion the potato mixture by scooping heaping tablespoons and rolling gently between your hands into 1 1/4-inch diameter balls. Arrange formed balls on a tray.
03 - Prepare three shallow bowls: add all-purpose flour to one, beat two large eggs in the second, and pour breadcrumbs into the third.
04 - Coat each ball in flour, then dip in the beaten eggs, and finally roll in breadcrumbs, ensuring a full, even coating. Transfer to a tray.
05 - Refrigerate the coated potato balls for a minimum of 20 minutes to firm for frying.
06 - Heat vegetable oil to 350°F (175°C) in a deep fryer or heavy-bottomed pot. Confirm temperature with a deep-fry thermometer.
07 - Working in batches, lower chilled balls into the hot oil using a slotted spoon. Fry, turning occasionally, until all sides are crisp and golden brown, about 2–3 minutes per batch.
08 - Remove fried balls from oil with a slotted spoon and drain excess oil on paper towels. Serve hot for optimal texture.