- For larger potatoes, preheat oven to 425°F.
- For roasting new potatoes, preheat to 400°F.
- Put each potato in the bowl of a wooden spoon, like you would carry an egg in an egg-spoon race, and cut across at about ½-inch intervals.
- Put cut potatoes on the baking pan on the stove with the butter and oil and heat till sizzling.
- Turn potatoes well, putting them in upside down (i.e., cut-side down) first, then right side up, and spoon the fat over them.
- Sprinkle each potato well with salt and put in oven.
- Cook large potatoes for about an hour and 10 minutes, testing to see whether the flesh is soft (forty minutes for the new potatoes)
- Transfer to warmed plate and serve.