For the egg pit, lightly grease four ovenproof glasses (approx. 220 ml each) up to almost halfway. Whisk eggs and milk. Season well with salt, pepper and nutmeg. Distribute evenly in the glasses.
Seal with aluminium foil and place in a wide pot. Place the pot on the stove and pour boiling water over it, so that the glasses are half in the water. Cover them and let them simmer at low heat for about 20 minutes.
For the Häckerle peel onion and dice very finely. Peel beetroot (put on disposable gloves), wash and finely dice. Heat the oil in a pan. Sauté the onion and beetroot over a low heat for 3-4 minutes.
Sprinkle with 1 1⁄2 tsp. sugar and caramelise briefly. Deglaze with vinegar, bring to the boil once. Season to taste with salt and pepper. Remove from the heat and let it cool down a bit.
In the meantime, wash the chives, shake them dry and cut them into fine rolls. Approx. 3⁄4 under the red beets lift.
Carefully lift the eggs out of the pot and dry the glasses. Let the egg whites cool down. Distribute red beetroot evenly into the four glasses. Pluck the fish and spread it on top. Sprinkle with the rest of the chives.