Add all the ingredients into a food processor. Pulse together until you have a smooth consistency. If the pesto is quite thick add more olive oil as required and continue to pulse.
Sever on fresh bread, with pasta or try mixing through steamed or roasted vegetables. Store any extra pesto in an air tight jar and top with a little extra oil to preserve.
Recipe by The Sidings N21 at http://www.thesidingsn21.co.uk/kale-and-walnut-pesto/