Combine the chickpeas, tahini, salt, salt, garlic, 3/4 cup water and 5 tablespoons of the lemon juice in a food processor and process until smooth and pureed. While the motor is running, pour in the oil and process until fully incorporated. Season with pepper. Transfer to a bowl and refrigerate for 6 hours to let the flavors to come together.
Just before serving, stir in the parsley and remaining 2 teaspoons lemon juice. Drizzle with oil and serve with flatbreads and olives. The hummus will keep in the refrigerator for up to 2 days.