Whisk the yolks together with the icing sugar in a bowl set over a bain-marie until frothy. Peel and pit the mangoes. Place the pulp into a blender and add the lime juice. Mix the mango purée together with the other mixture. Add the whipped cream. Pour into a parfait mould or, failing that into a mould of your choice. Put in the freezer for at least 4 hours. To remove from the mould, plunge the mould in hot water for a few seconds. Decorate with pieces of mango.