Toast the hazelnuts or almonds in the oven until they begin to turn golden and smell toasty, about 8 minutes. Remove from the oven and, is using hazelnuts, transfer them to a paper bag or a tea towel which you must close around the nuts so they steam slightly and their skins blister away from the nuts. Note that hazelnuts tend to roast unevenly, and you may need to return some of them to the oven to continue roasting. When the hazelnuts are cool, rub them in the towel or bag to remove as much of the papery skin as possible. For almonds, they toast more evenly and do not need skinning.