For about 6 to 8 people
If the potatoes are regular medium sizse, then pre-heat the oven to 425 (F), if you are using smaller new potatoes, then pre-heat the oven to 400 (F) as they take less time to cook.
Leave the peal on the potoate. Make a series of cuts in each potatoe. Put each potatoe in the bowel of a wood spoon and cut across each at about 1/2 inch intervals. The cuts go about 3/4 of the way through the potatoe.
Coat the potatoes with the butter and oil, and place the cut potatoes in a shallow roasting pan or cooking sheet. Bake until they sizzel then turn them and coat with some of the butter/oil.
Sprinkle the potatoes with salt and return to the oven. The larger potatoes need about an hour, about 45 minutes for smaller or new potatoes.
This recipe is from Nigella Lawson and I found it featured on Oprah's web site. It has always gone over as a big hit.