Boil potatoes
Cook cubed potatoes in salted water until fork-tender (about 10–15 minutes). Drain well.
Mash & mix
Mash potatoes, then stir in butter, sour cream, milk, salt, pepper, and about half the cheese.
Layer it up
Spread mixture into a greased baking dish. Top with remaining cheese and bacon.
Bake
Bake at 375°F (190°C) for 20–25 minutes until hot and bubbly.
Finish
Sprinkle with green onions before serving.
