Clean the cauliflower, cut into florets, wash. Pour into 200 millilitres of boiling salted water. Season with nutmeg, cover and cook over medium heat for about 15 minutes. In the meantime, hard-boil the egg, rinse with cold water and peel.
Finely dice the egg, except for one slice for garnishing. Roast sunflower seeds in a dry pan. Wash the chives and cut into small rolls. Bind cauliflower water with sauce thickener, refine with sour cream.
Stir in chopped egg and chives. Season to taste with salt, pepper and nutmeg. Sprinkle with sunflower seeds and serve garnished with ice cream and parsley leaves.