Cold Cucumber Soup (Tarator / Liquid Tzatziki)

Name: Cold Cucumber Soup (Tarator / Liquid Tzatziki)
Prep time: 10 min
Total time: 10 min
Cuisine: European, Mediterranean, Greek
Ingredients: 1 cucumber, medium size; 15 oz (400g) plain Greek Yogurt; 1 cloves garlic (optional ); 1 tbsp olive oil (exstra virgin ); 1 tsp dill (fresh/dried) (finely minced ); a handful of chopped walnuts (or other nuts) (to taste ); pinch of salt (to taste)