Break the chocolate in small pieces.
Put the chocolate and whip cream in a casserole and turn on medium heat. Stir all the time until the chocolate is melted.
Take away the casserole from the stow and let it cool down.
Pour 1 egg yellow at the time in the mixture and stir together with an electrical mixer. If the mixture gets to compact add some fluid whip cream. Make sure the mousse is smooth.
Place the mousse in small portion bowls and keep cold until it is time to serve.