This super simple casserole is comfort food at its best!
Preheat oven to 350ºF. Chop onions; sauté onions in 1 tablespoon butter until translucent; set aside. Melt remaining butter.
In a large bowl, whisk together soup and sour cream, then add half of melted butter, seasoned salt and garlic powder.
Transfer potato mixture into heatproof baking dish. Combine cornflakes and remaining melted butter and sprinkle evenly over top of casserole.
Bake for 40-45 minutes or until heated and bubbly.