Preheat the oven to 425 degrees F.

Add chopped cauliflower and sliced onion on a large nonstick or greased baking sheet. Toss the cauliflower with 2 tablespoons olive oil and season with salt and pepper.

Place in oven for 30-35 minutes. Flip the veggies over about halfway through.

Add butter in a soup pot over medium heat. Let the butter melt then add in the minced garlic. Cook the garlic for about 1 minute or until fragrant.

Pour the vegetable broth into the soup pot with the garlic and turn up the heat to medium-high.

Remove the cauliflower from the oven and add it and the onions to the soup pot. Season with nutmeg and a little salt and pepper.

Bring soup mixture to a simmer. Then cook for about 15 minutes.

Remove the pot from heat and allow soup to cool slightly before pouring into the blender. 

Blend in blender until creamy (may need to do in batches so as not to overfill blender). Or, if you have an immersion blender, you could use that instead right in the pot.

Pour the soup back into the pot if using a blender. Give it a taste. If you like yours a little saltier, stir in a generous sprinkling of salt and give it another stir.

Scoop into bowls and serve warm garnished with some chopped fresh parsley and a few small pieces of roasted cauliflower if desired.