Dry roast the walnuts in a cast iron skillet on medium heat for about 8-10 minutes or until golden brown and fragrant. DO NOT burn. Set aside and cool to room temperature.
Combine toasted walnuts with the walnut oil and garlic cloves and puree in blender until smooth.
Add chickpeas, orange zest, orange juice, salt and pepper and continue to blend to a smooth consistency. Add some of the reserved garbanzo bean liquid if you think it's necessary for thorough blending and also for the consistency you prefer. Adjust seasoning if necessary.
Transfer hummus to a serving bowl. Serve with pita bread, tortillas, sliced French bread, cut up vegetables, etc.