01 - 
                Throw the potato mash, grated cheese, diced scallions, egg, and 3 tablespoons flour into a big bowl. Stir everything until it's well blended.
              
              
              
                02 - 
                Split the mix into 12 equal bits with your hands. Make each bit into a small ball, then squish it down to form a cake about 1/2 inch thick.
              
              
              
                03 - 
                Put the other 1/2 cup flour in a flat dish. Roll each cake in the flour until they're totally covered.
              
              
              
                04 - 
                Pour 3 to 4 tablespoons oil into a big frying pan over medium heat, making sure the whole bottom is covered with oil.
              
              
              
                05 - 
                Fry the cakes in batches until they're golden and crunchy on both sides, roughly 3 to 4 minutes per side. Don't crowd the pan and wait long enough before flipping them.
              
              
              
                06 - 
                Put the cooked cakes on a paper towel plate and sprinkle salt on them right away. Serve with a dollop of sour cream and extra scallion bits on top.