To make this soup, start by heating a large pot, on the stove, over medium heat, and add in the olive oil.
While the pot is heating up, wash and chop the leeks, using both the whites and the greens, and mash the garlic.
Then, add the chopped leeks and mashed garlic to the hot oil and cook for about 5-6 minutes, until the leeks begin to soften.
Then, stir in the chili flakes, nutmeg, black pepper, and sea salt. Add in the cauliflower and broth, then place the cover on the pot.
Allow the soup to cook, covered, for about 25 minutes. Then, turn the heat off.
Remove the cover and stir in the freshly-grated parmesan cheese.
Then, transfer the soup to a blender and blend until it's pureed and smooth. I like to leave a little bit of texture in the soup, but the consistency is up to you. You can also use a hand-held immersion blender for this.
Once the soup has reached your desired consistency, taste and adjust the salt and pepper as needed.
Finally, divide the soup amongst bowls, garnish with some chopped parsley, parmesan cheese, and a drizzle of olive oil, if desired, then serve and enjoy!