Melt the chocolate in a saucepan over a water bath.
Beat the egg white until stiff, finally add the sifted powdered sugar and refrigerate. Whip the cream until stiff and chill.
Mix the cream and egg white while cold and fold in the lukewarm chocolate quickly and refrigerate.
Sugar syrup:
Simmer sugar and water in equal parts for about 15 minutes with a cinnamon stick and orange zest.
Mango puree:
Peel the mangoes and cut into small pieces. Then simmer in the sugar syrup for about 10 minutes. Then let the mixture cool down and puree with the blender.
Serve the mousse with the mango puree, decorate with mint leaves if you like.