You can use raw or cooked potatoes for fried potatoes. Call them “sauteed” if you want to sound healthier! If I have raw potatoes I tend to peel them. If I have (or create) leftover baked potatoes, I just dice them. In fact, I’ll sometimes make extra baked potatoes so I can make these quickly the next morning or night.
Dice the potatoes. Heat some butter and olive oil (half and half, maybe 1 Tbs or less per large potato). Add the potato and cook over medium heat, stirring initially to coat the potatoes and periodically after that to get them evenly browned. Cooked potatoes take less time, of course. Sprinkle with salt and pepper near the end of the cooking time. Add some diced onions if you like. Green peppers are good also.
I’ll serve these for dinner as a side dish to just about any dish. I serve them for breakfast either with eggs or mixed into breakfast burritos.