1) Heat oil in skillet on medium high heat and add chopped onion and minced garlic. Cook for 1-4 mins, until tender. Add lemon juice and cook for 1 min. Add cucumbers (3¾ of it) keep rest for garnish. Add broth, salt and pepper and bring to simmer until cucumbers are soft (about 6-8 mins).
2) Transfer the soup to blender, add avocado and parsley and blend until smooth.
3) Pour into serving bowls, garnish with cucumber and add yogurt.