Remove about a half cup and reserve.
Add lemon juice, yogurt, olive oil, cumin, coriander and sugar, and process till smooth, scraping down sides of bowl.
Transfer to a mixing bowl and add the reserved chopped garbanzos, combining well with spoon.
Taste and correct seasonings.
Transfer to serving bowl and garnish with chopped fresh parsley and a dollop of olive oil.
Note: I put fresh lemons in the microwave for about 30-45 seconds
before juicing them...I get a lot more juice from them this way.