Add olive oil to a large pot. Cook onion, garlic, and red chili flakes for 3-4 minutes.
Add all the cauliflower and cook for at least 5 minutes, until it is more tender but not all the way cooked.
Add water (or vegetable stock), bring the contents of the pot to a boil, reduce heat to medium-low, cover, and simmer for 10 minutes.
Let the pot cool off a little before blending with lemon juice, nutmeg, black pepper, nutritional yeast and salt.