Whip the cream and the egg whites in separate bowls. Fold the sugar into the egg whites to make a meringue. Bloom the gelatine and dissolve in the warm cordial. Mix the cordial into the meringue. Fold the cream and the yoghurt into meringue. Place into six glasses and refrigerate.
Place the sugar in a large frying pan and caramelised. The sugar will need to caramelise and reach the hard ball stage for the praline to set. When the sugar is a rich brown colour, add the hazelnuts. Spoon the sugar over the hazelnuts. When completely covered, pour the praline on to a silicone mat. When cool and solid, blend the praline into a rough powder.
Sprinkle the strawberries with a little sugar and allow to macerate.
Sprinkle some praline over the mousse. Garnish with some strawberries and some flowers.