A candlenut is a hard, oily, tropical nut. Because of their high oil content, candlenuts were once used to make candles. The nuts are usually crushed and added to soups, or ground and used as a thickening agent in Indonesian and Malaysian cooking, particularly in curries and satays. The raw nut is slightly toxic so it must be cooked before it is safe to eat. Buy candlenuts in Indian and Asian supermarkets and store in the fridge. If candlenuts are unavailable, substitute them with macadamia nuts.