Add all ingredients except the chicken to a food processor or blender. Process until combined. If the sauce is a little thick, add a splash of water or extra lemon juice.
Place the chopped chicken in a bowl and add approximately 1 cup of the sauce; stir through until coated. Add more sauce until the salad is your preferred consistency.
This is best eaten straight away as the zucchini will release water into the mixture that will make the salad separate. If you’re making this ahead of when you’ll serve it, pop the processed zucchini mixture into a sieve over a bowl in the fridge and leave there until chilled. Discard the liquid that drains through the sieve before folding the chicken into the zucchini mixture.