Old Fashioned Potato Cakes

2 cups mashed potatoes

1 cup all-purpose flour

1 onion, diced

1 egg

½ teaspoon ground black pepper

½ teaspoon salt

½ cup vegetable oil, or as needed

Mix mashed potatoes, flour, onion, egg, black pepper, and salt together in a bowl until batter consistency.

Heat vegetable oil in a skillet over medium heat. Drop 4-inch circles of batter into hot oil. Cook until golden brown, about 5 minutes per side. Remove with a slotted spoon and drain on paper towels. Repeat with remaining batter.