Preheat the oven to 110°C, fan 90°C/lowest gas mark.

To make the meringue: line 2 large baking trays with parchment paper and draw 16 circles about 8cm diameter on the surface.

Place the egg whites into a spotlessly clean glass bowl and whisk until soft peaks form.

Add the caster sugar a spoonful at a time until the egg whites are glossy and form stiff peaks. Whisk in the vinegar, cornflour and rose water until totally combined. The eggs should be very thick and glossy.

Place a little meringue at the corner of each sheet of parchment paper to hold it to the tray.

Fit a piping bag with a 13mm star nozzle. Turn the piping bag inside out and run four lines of food colouring down the sides, from the tip towards the open end (this will create swirls when you pipe out the meringue roses). Turn the piping bag the right way round and fill with the meringue mixture.

Pipe it on to the circles, working from the centre outwards in a spiral shape to make thick roses.

Bake in the oven for 1 hour, then turn the oven off, leaving the meringues in the oven. They will continue to cook as the oven cools down.

When cold remove and peel off of the paper.

While the meringues are cooling, make the chocolate ganache – tip the dark chocolate into a medium bowl set over a pan of simmering water and leave to melt.

When the chocolate has melted, stir well then remove from the heat and pour the cream onto the melted chocolate, whisking all the time until smooth.

Set aside to cool to room temperature, then whisk to smooth through then decant into a piping bag.

Pipe the chocolate ganache onto the flat side of 8 meringues, then sandwich the remaining meringues on top.

Serve in a big pile, with the dried rose petals scattered over.