melt the chocolate
Add chocolate chips or chopped chocolate to a large bowl and set it over a saucepan filled with water. Make sure the bowl doesn't touch the water. Cook over low heat until the chocolate is melted, stirring occasionally. In a separate saucepan bring 50g of whipping cream to a boil, then immediately remove from the heat and pour over the melted chocolate. Stir to combine to get a nice, glossy texture. Leave to cool at room temperature.
whip the egg whites and whipping cream
In a bowl whip the egg whites using a mixer. Gradually add the sugar and a pinch of salt. Beat until firm peaks form. In a separate bowl whip 100g whipping cream until soft peaks form (make sure to use clean beaters).
Stir 1/3 of whipped cream and egg whites into cooled chocolate mixture, then gently fold in the rest with a rubber spatula. Spoon your chocolate mousse into serving cups and place in a fridge for at least 3 hours or even better overnight.
Bring chocolate mousse to room temperature before serving (30 minutes). Top with whipped cream, shaved chocolate, cocoa nibs or chopped hazelnuts if desired. Store in a fridge for up to 3 days. Enjoy.