Clean and wash the cauliflower and divide it into small florets. Peel and finely chop the onion.
Heat 2 tablespoons of fat. Sauté the onion in it. Dust with flour and sauté briefly. Good 1⁄2 Stir in l water and milk, bring to the boil. Add cauliflower and stock. Cover and simmer for about 15 minutes.
Remove some cauliflower florets after 6-8 minutes.
Coarsely chop the pistachios. Wash the cress and cut it from the bed. Heat 1 tablespoon of fat in a frying pan. Fry the cauliflower florets for 2-3 minutes, turning them over. Season with salt and nutmeg.
Finely puree the soup. Stir in crème fraîche and season to taste with salt, pepper, nutmeg and lemon juice. Serve the cauliflower soup. Arrange florets, cress and pistachios on top.