Easy cheesy potatoes

3 pounds diced potatoes or 30 ounces country-style hash browns
1/4 cup butter, melted
1 cup sour cream
1 cup cream of chicken or cream
  of cheddar soup
1/4 cup green onion, chopped
2 cups cheddar cheese, divided

Preheat oven to 375 degrees and grease a 9-by-13 baking dish. If using fresh potatoes, place in a saucepan with cold water and simmer 12-14 minutes or until fork-tender. Drain and allow to cool slightly. Melt butter, add sour cream, soup, onion and 1 1/2 cups cheese. Toss in the potatoes (or frozen hash brown potatoes) and combine. Spread into prepared baking dish. Top with remaining cheese and bake 28-30 minutes or until browned and bubbly. For a crunchy topping, combine 1 1/2 cups corn flakes, slightly crushed, with 4 tablespoons melted butter and top casserole before baking.