Preheat oven to 350 degrees F (180 degrees C). Boil Potato (6) and allow them to cool completely.
Grate poatoes and put into a large bowl (I usually keep the skins on; most of the skins will be easy to remove at the end of grating each potato.)
Combine Butter (1/2 cup), Cream of Chicken Soup (10.5 ounce), Scallion (1/2 cup), and Sour Cream (1 pint). Mix well.
Add half the Cheddar Cheese (1 1/2 cup) to the potato and mix lightly and gently together.
Add the sour cream mixture to the potato mixture.
Spread mixture into a 9x13 inch casserole pan. Sprinkle with Salt (to taste) and Ground Black Pepper (to taste).
Top with remaining Cheddar Cheese (1 1/2 cup).
Sprinkle with Corn Flakes (2 cup).
Drizzle 1/4 cup butter over crushed cornflake crumbs.
Bake for 35 to 45 minutes