To make the candied walnuts, put the sugar and water into a pan and bring to the boil, stirring gently once. Simmer until the sugar has dissolved and the syrup thickened slightly. Add the walnuts and cook for 2-3 minutes. Empty the pan contents onto a sheet of silicone paper. Pour enough vegetable oil into a sauté pan to cover the bottom by 2cm (¾in) and heat until just shimmering. Place the walnuts, a few at a time, into the hot oil for a couple of minutes until golden. Drain again on a fresh sheet of silicone paper and leave to cool.