Preheat oven to 350F. Spray a 9x13 pan with cooking spray.
In a large skillet, cook the ground beef along with the onion and celery, over medium-high heat until no longer pink.
Drain excess liquid if desired.
Stir in the corn. Set aside.
In a separate bowl, combine the soups and milk, stirring with a whisk to fully incorporate.
In the prepared baking dish, layer half the ground beef mix. Top with half the sliced potatoes. Season with salt and pepper.
Spread half the soup mixture over the potatoes, top with half the cheese.
Repeat with remaining meat mixture, potatoes, soup mixture, and finish with cheese.
Cover with foil and bake for 1 hour.
While baking, combine the melted butter with the cornflakes.
After the 1 hour, remove the foil and top with cornflake crumbs.
Bake uncovered for 5-10 minutes or until the top is lightly browned and the potatoes are fork tender.
Remove, garnish with fresh parsley, and serve.