Beat the egg yolk, egg and sugar in a double boiler to make the rose. Whip the cream until stiff and stir in the soaked and squeezed gelatine.
Melt the white chocolate and nougat and mix everything together. At least 2 hours in the freezer.
For decoration: Drain 4 half Williams-Christ pears, whip 50 ml cream until stiff and pour into a piping bag. Place half a pear on each of the parfaits and sprinkle a rim of whipped cream.