01 -
Preheat the oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish with nonstick spray or butter.
02 -
In a large mixing bowl, combine frozen hashbrowns, diced onion, melted butter, cream of chicken soup, sour cream, 1 cup of shredded cheddar cheese, kosher salt, and black pepper. Mix thoroughly until evenly blended.
03 -
Evenly spread the potato mixture into the prepared baking dish, pressing gently to distribute.
04 -
Scatter the crushed cornflakes over the surface of the hashbrowns for a crispy topping.
05 -
Transfer the dish to the oven and bake uncovered for 45 to 50 minutes, until the casserole is bubbly and golden brown on top.
06 -
Remove the casserole from the oven and sprinkle the remaining 1 cup of shredded cheddar cheese across the surface. Return to the oven for an additional 5 to 10 minutes, or until the cheese is fully melted.
07 -
Allow the casserole to cool for several minutes before slicing. Serve warm.