Method
1. First make the sauce. Heat the extra virgin olive oil and butter in a pan, add the anchovy fillets and cook, stirring over a gentle heat, until they have almost dissolved into the oil. 2. Add the shallots and courgette and cook until the shallots begin to soften, then add the stock, bring to the boil and simmer for one minute. 3. Stir the rocket, season with black pepper and simmer for a couple of minutes.4. Remove from the heat, allow to cool slightly, then mix in a blender until smooth. 5. Return to the pan and stir over a high heat with a wooden spoon until nearly all the liquid has evaporated and the sauce becomes creamy.