Take the cucumber and pat it down with kitchen towel to remove the excess water, as you don't want the water to run out into the yogurt later on. Place it in a bowl with all the other ingredients, except the crushed walnuts and yogurt/quark, and gently combine together. Set aside to marinate for at least 15 minutes.
Add in the yogurt/quark and stir together until combined well then cover over with cling film or paper and leave to set in the fridge for at least an hour.
When ready to serve, either spoon it into small bowl or mould and turn out neatly onto the plate, then sprinkle the walnuts over the top and garnish with a few parsley leaves. Eat and enjoy! :)
