Fry the Bacon (5 slice) over medium heat, about 8-10 minutes. Drain the excess grease on a paper towel. Chop the bacon.
In a bowl, add Mashed Potatoes (4 cup), Scallion (1/2 cup), chopped bacon, Salt (to taste) and mix together until well incorporated.
Using your hands, take a bit of the mixture and form it into a patty. Press a piece of the Cheddar Cheese (to taste) in the center and roll the mashed potato into a ball around it. Repeat with the rest of the mixture. Chill in the fridge for 20-30 minutes.
Heat the Oil (as needed) over medium heat until hot, about 350 degrees F (180 degrees C). Have your Breadcrumbs (1 1/2 cup) and Large Egg (2) in separate bowls ready by the stove. Drop a ball in the egg, then roll in the breadcrumbs. Put the ball back into the egg and again into the breadcrumbs. Fry for 2-3 minutes. Drain on a paper towel.