Place a heavy duty pan over medium high heat. Add in the butter, garlic, eggplant, potatoes, celery, and onion. Stir together well and let cook until everything is tender, about 20-25 minutes. Once tender add in the cumin, red pepper (if using), parsley, salt and pepper and stir together well and cook for another 5 minutes.Next add in the vegetable stock and stir together until well combined. Cook until soup starts to thicken -- about 30-40 minutes. Finally, turn off the heat and slowly stir in the cream. Once well combined, serve soup.