Soak cashews overnight in cold water or in boiling water for 10 minutes
Drain cashews and add to a blender or food processor (or hand-held blender) along with all other ingredients other than chopped parsley
Whizz until completely smooth
Stir through the chopped parsley
Taste and adjust seasonings accordingly
Keeps covered in the fridge for up to a few days
Notes
*For a nut-free or easier version, you can substitute with mayonnaise (vegan if necessary). If going this route, grate your garlic clove before mixing it in. No need to grate it in if you're using the blended version.