Heat oil and butter over medium heat in a large stock pot. Add celery, carrots and onion and sauté until tender. Season with salt and pepper.
Add butternut squash and chicken stock. Bring to a boil. Reduce heat and simmer until the squash is tender. Puree soup using an immersion blender or food processor.
Add Harissa Sauce, chickpeas and zucchini. Simmer 10 minutes or until the zucchini is tender. Serve garnished with parsley or cilantro.