Place extra-virgin olive oil, lime juice, 2 tablespoons water, tahini and half of garbanzo beans in food processor and process until smooth.
Add remaining ingredients and process, pausing, mixing with spatula and processing again until smooth. If it is too thick, add another 2 tablespoons of water. Adjust salt to taste.
Transfer to a bowl, cover and refrigerate for one hour. Can be made one day ahead.