In a mixing bowl, combine the leftover mashed potatoes, flour, grated cheese, egg, chopped green onions, garlic powder, salt, and pepper.

Use a whisk or fork to blend everything until smooth and well incorporated.

Heat a non-stick skillet over medium heat and add a bit of oil or butter.

Take about 1/4 cup of the batter and form it into a patty. Press it down slightly for even cooking.

Place the patty in the skillet and cook for about 3-4 minutes on each side, or until golden brown.

Continue to cook until all the batter is used, adding more oil or butter as needed.

Once cooked, place the pancakes on a paper towel to drain any excess oil.

Serve the pancakes warm with your favorite toppings, such as sour cream or applesauce.