Break the cauliflower into florets, and cook in salted, sugared water (1 tsp salt, 1 tsp sugar) for 8-10 minutes, until still slightly resistant to a fork but tender.
Drain thoroughly in a colander, and arrange on a salad plate.
Push the hard-boiled egg yolks through a sieve or mash with a fork, and season with salt.
Stir in the sour cream, the vinegar, the mustard and the oil, until smooth.
Stir in the finely chopped chives.
Pour the dressing over the warm or cooled cauliflower.
Serve cold, as a starter or light lunch.
Based on: Malatinszky Fanny szakácskönyve (a classic Hungarian cookbook), modernised. Calories and protein are estimated.