To roast, preheat oven to 350°. With a small, sharp knife, cut an X through the shell on the flat side of each nut. Place nuts in a shallow pan and roast until skins open at Xs and nuts are tender inside (open one to check), 25 to 30 minutes. When they're just cool enough to handle, squeeze them in a towel to loosen shells, then peel away shells and tough inner linings.