Heat the butter or oil in a stock pot or Dutch oven over medium heat.
Saute the onion, celery, and garlic for 3-4 minutes.
Add in your diced zucchini and season with a pinch of sea salt and pepper.
Add in your broth and cook, stirring often, for 8-10 minutes or until zucchini has softened.
Remove from heat and stir in the parmesan cheese.
Use a handheld immersion blender, and blend until smooth.
Serve while hot and enjoy!