Spray one large soup pot with olive oil flavored cooking spray. Place pot over medium high heat and sauté celery, onion and cauliflower until tender. Add asparagus, artichokes and seasoning and stir until well combined in pot.
Add artichoke broth and bring soup to a boil. Remove soup from heat and with hand held blender puree soup until smooth.
Return soup to medium heat and add cream. Stir until well combined. Garnish with dollop of sour cream and fresh celery leaves.