Bring the potatoes and enough water to cover them by an inch to a boil, reduce the heat and simmer until a fork can easily be pushed into them, about 15-30 minutes depending on the size of the potatoes, before draining them.
Place the potatoes on a greased baking sheet and 'smash' them by pressing down on them with something like a potato masher, the bottom of a gloss or bowl, etc.
Brush the potatoes with oil, season with salt and pepper and bake them on the top shelf of a preheated 450F oven until golden brown and crispy on top, about 20 minutes.Meanwhile cook and crumble the bacon.
Sprinkle the cheddar onto the potatoes and optionally broil for a minute to melt the cheese.Top with the sour cream, bacon and green onions and enjoy as a side or as an appetizer!