Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
Place potatoes in a large pot and cover with water. Bring to a boil and cook for 10 minutes, or until potatoes are tender. Drain and transfer to the prepared baking dish.
Melt butter in a small saucepan and stir in sour cream. Pour over potatoes and stir to combine. Sprinkle with cheddar cheese, green onions, and bacon.
Bake for 20 minutes, or until cheese is melted and bubbly.
Season with salt and pepper to taste and serve.
Interesting Facts
The casserole can be made ahead of time and stored in the refrigerator for up to 3 days.
The casserole can also be frozen for up to 3 months.
Feel free to add other ingredients to the casserole such as diced ham, cooked broccoli, or other vegetables.