Make the delicate pastel meringues the day before, with fresh or dried lavender, then add the cream before serving.
Preheat the oven to 130C/250F/Gas ½. Line a large baking tray with baking paper.
Grind the lavender flowers in a mortar and pestle for 1-2 minutes, or until fragrant.
In a large bowl, whisk the egg whites using an electric whisk until stiff peaks form when the whisk is removed.
Gradually whisk in the caster sugar, a tablespoonful at a time, until all of the caster sugar has been incorporated into the mixture and the mixture is thick and glossy.
Sprinkle one tablespoonful of the ground lavender flowers over the egg white mixture and whisk until combined.
Dip a cocktail stick into the food colouring mixture and shake off a drop of food colouring into the egg white mixture. Whisk well, adding more food colouring until the egg whites are a uniform pale mauve colour. (NB: You may not need all of the food colouring.)
Spoon the meringue mixture into a piping bag fitted with a large plain nozzle. Pipe 32 small swirls of the meringue mixture onto the prepared baking tray.
Transfer the meringues to the oven and immediately reduce the temperature to 100C/225F/Gas ¼. Bake the meringues for two hours, or until crisp but not coloured. Turn off the oven and leave the meringues inside until the oven is cool. When the meringues have cooled, store them in an airtight tin until needed.
No more than 30 minutes before serving, pour the cream into a mixing bowl and sift over the icing sugar. Whip using an electric whisk until soft peaks form when the whisk is removed.
Place a teaspoonful of the cream mixture onto the base of one of the lavender meringues, then sandwich the cream between a second meringue. Place onto a large serving plate. Repeat the process with the remaining meringues, then serve immediately.
