Melt the milk chocolate au bain-marie: break the chocolate into pieces and place them in a bowl over a pan of hot water. Make sure the bowl does not touch the pan, so the chocolate melts slowly without burning.

While the chocolate melts, prepare the egg whites: use a grease-free bowl to beat the egg whites until stiff peaks form. Gradually add the sugar while mixing. Be careful not to overbeat the egg whites, so you can easily fold them into the melted chocolate without losing too much air.

Whip the heavy cream in a separate bowl until it forms soft peaks.

Gently add the melted chocolate to the whipped cream. Fold the chocolate in slowly until everything is well combined.

Next, add the stiffly beaten egg whites to the mixture and fold them in. Be careful not to mix for too long to prevent losing the air.

Divide the chocolate mousse into glasses and refrigerate for at least 3 hours to set.

Garnish the chocolate mousse before serving with some grated chocolate if desired. Enjoy!