Roughly chop the chocolate and place it in a microwave safe bowl.
Melt in the microwave at 30 second increment until fully melted.
In a medium sized bowl or a stand mixer bowl, separate the yolks from the whites. Placing the cold egg white in the stand mixer bowl and the egg yolks with the melted chocolate one at a time. Mix the egg yolks into the melted chocolate well between every addition.
Whip the egg whites using a whisk attachment until stiff peaks form then slowly fold in about 1/3 of the egg white mixture into the chocolate mixture. Repeat the process again twice with the 2/3 leftover egg whites.
Pour the chocolate mousse mixture in your serving glasses and chill for at least 3 hours. Serve as is or topped with whipped cream and shaved chocolate and enjoy!