Begin by ensuring your hash browns are fully thawed. Either defrost them in the refrigerator overnight or arrange them on a baking sheet and place in a 200°F oven for roughly 20 minutes until no longer frozen.
Set your oven to preheat at 350°F.
In a large mixing bowl, combine the sour cream, cream of chicken soup, 6 tablespoons of the melted butter, salt, black pepper, and dried minced onion. Stir the ingredients until the mixture is smooth and well blended.
Fold in the thawed hash browns and the shredded cheddar cheese, mixing just until evenly coated. Transfer the mixture to a 9x13-inch baking dish and spread into an even layer across the bottom.
Place the corn flakes in a large zip-top bag and lightly crush them using your hands or a rolling pin until they’re broken into small flakes. Drizzle in the remaining 4 tablespoons of melted butter, seal the bag, and shake or massage until the flakes are evenly coated.
Sprinkle the buttery cornflake topping generously across the surface of the potato mixture in the baking dish.
Bake uncovered for 40 to 50 minutes, or until the casserole is bubbling at the edges and the topping is golden brown and crisp.
This dish pairs beautifully with baked ham, roast turkey, or grilled flank steak for a hearty, comforting meal.