In a blender, add yoghurt cucumbers, mint, dill and lemon zest and blend for 30 seconds.
Add water and blend for a couple of seconds till you get a smooth creamy consistency. Depending on the brand of yoghurt you use, you may need to adjust water to get the creamy consistency of thick cream.
Salt to taste.
Chill for 15-20 minutes in freezer.
Stir in 1/4 cup each of walnuts and raisins.
Plate and garnish with mint, dill and rose petals (optional)