Peel and rinse the potatoes, cut into quarters and cook in boiling salted water with the lid on for 20 minutes.
Heat milk, butter, a little salt, pepper and nutmeg. Cut 3/4 of the chives into fine rolls.
Drain the potatoes and steam them in the open saucepan on the turned off plate. Press the cooled potatoes through a potato ricer or possibly mash them finely and gradually fold in the hot milk mixture with a wooden spoon. Season with salt, pepper and nutmeg. Fold in the chive rolls and fried onions.
Spread the puree into a mold about 30 cm long. Using the back of a damp spoon, press 6 wells into it, crack in the eggs and sprinkle with cheese.
Bake in a heated oven at 200 °C on the 2nd rack from the bottom for 22-25 min (convection oven not suitable).
Cut the remaining chives into long rolls, mix with a little bit of salt and pepper and spread evenly on the casserole.
Our tip: Always use fresh chives if possible!