This is not an original recipe, but it is worth repeating. Bake sweet potatoes, wrapped in tin foil, for about an hour. Roast chopped walnuts in a 350°F oven, on a cookie sheet, for five minutes. While roasting the walnuts, heat 1/2 cup of white sugar in a saucepan, stirring until the sugar just browns. Then add the walnuts to the saucepan, coating them in the sugar. Remove from heat. Dust with salt. Top the potatoes with vegetable spread and candied walnuts.