Melt couverture in bain–marie and add the olive oil and liqueur
Mix the yolks with half of the sugar and whisk until smooth.
Mix the chocolate into the yolk mixture.
Whip the egg whites with the rest of the sugar and the salt into firm peaks to make the meringue.
Blend together the meringue and the chocolate mixture and stir in ¾ of the orange shavings. Whisk gently until the mixture becomes smooth.
Put the mousse into bowls or glasses.
Place them in the fridge for at least 3 hours.
Serve adding orange shavings on top of each portion.