Once drained, combine the chickpeas with salt, pepper, 3 tablespoons olive oil, and 1/4 cup of the reserved chickpea liquid in a food processor. If using a blender, this step will need to be done in two batches. Pulse the food processor to blend the ingredients. Then turn the food processor to high, slowly adding the remaining olive oil and reserved chickpea cooking liquid as needed until smooth and of the desired consistency. Before serving, place in bowl, drizzle additional olive oil on top, and season with freshly cracked black pepper. Serve with pita bread, carrots, peppers, and cucumbers.