Preheat oven to 400°F. Line a baking sheet with parchment paper and put onion, garlic, carrots, celery, and chopped cauliflower onto the pan.

Drizzle with olive oil, sprinkle lightly with salt and pepper, toss to coat, then roast for 25-30 minutes, until vegetables are caramelized in spots.

Add the whole pan of roasted vegetables to Dutch oven. Add broth and turn heat to medium high until a high simmer is reached.

Stir and reduce heat to medium low, cook for 15-20 minutes.

Turn off heat and add the heavy cream, nutmeg, and lemon zest.

Fit the pan guard onto your KitchenAid® Cordless Hand Blender blending arm, then attach the arm to the motor body.

Fully submerge the blending arm into the soup and, with the arm at a slight angle in the soup, press the variable speed controller for 2 seconds.

Submerge the blending arm in a different part of the pot and, while holding it at a slight angle, press the variable speed controller for 2 more seconds.

Proceed to blend portions of the soup in 2 second intervals until soup is creamy and some cauliflower florets remain for texture if desired.

Remove the blender from the soup. Taste for seasoning, adding salt and pepper if desired.

Stir in minced parsley and serve hot.