Clean and wash the cauliflower and cut it into very small florets. Peel and finely chop the onion. Peel garlic and chop finely. Heat butter in a pot. Steam cauliflower, onions and garlic for 2-3 minutes, then dust with flour and sauté briefly.
Season with salt. Add stock and milk and simmer covered for about 20 minutes.
Leave the bacon in a frying pan while turning it until crisp. Pour onto kitchen paper and let it drip off. Wash parsley, shake dry, remove leaves and chop finely. Season soup with salt and nutmeg.
Break up the bacon. Serve the soup. Sprinkle with parsley and bacon and serve immediately.