Wash the chives, dab dry and cut into fine rolls. Whisk eggs, milk, salt, pepper and nutmeg. Mix in the chives. Grease a small, flat casserole dish and pour in the egg milk.
Fill the fat pan of the oven 1-1.5 cm with boiling water. Carefully place the casserole dish in the water bath and cook in the preheated oven (electric range: 200 °C/ gas: level 3) for approx. 20 minutes. In the meantime, peel and finely dice the onion.
Clean and wash the carrots and cut them into fine slices. Heat the oil in a pot, fry the onion in it until transparent, deglaze with broth, bring to the boil. Add carrots and cook for about 8 minutes. Turn out the eggs on a board and cut into small rhombs.
Add the egg stab to the soup. Season soup with salt and pepper. Serve in soup plates. Garnish with chervil as desired.