I parboil my potatoes, meanwhile heating about a couple of tablespoons of oil in a pyrex bowl in the hot/heating oven, drain potatoes and shake them about in the pan. Then I dip them into the hot oil with a slotted spoon and spread them on a tray and roast them. There is usually only just enough oil for them (if that) as the oil soaks into the bruised surfaces of the potatoes and roasts crisp, while the insides are soft. The tray gets scraped to get all the scraps off, and there is no loose grease left.
If the spuds are slightly more parboiled than intended, there are a lot of disintegrating scraps (yummy)
The dipping performance produces loud sizzles and is watched with awed fascination by the family.