Heat butter in a medium saucepan over medium heat. Cook onion and celery until tender (do not brown).
Add cauliflower, broth and seasonings. Simmer uncovered 10-15 minutes stirring occasionally until cauliflower is tender.
Blend using a hand blender until smooth. Add heavy cream and simmer an additional 8-10 minutes or until thickened.
Season with salt & pepper to taste. Stir in parmesan cheese if using.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)