Cook the eggs in boiling water for about 10 minutes. Drain, rinse with cold water and let cool. Drain the shrimps. Mix cream cheese, sour cream, whipped cream and horseradish. Season to taste with salt and pepper.
Wash and clean spring onions and cut into rings. Grease 4 round gratin dishes (approx. 12 cm Ø). Peel and slice the eggs. Place the slices of egg in the moulds in flakes. Spread spring onions and shrimps on top.
Pour cream cheese cream in the middle. Crumble the rusk. Sprinkle rusk and cheese on the cream. Gratinate in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for about 5 minutes.
Serve garnished with chervil.