First make the rose petals. Set the oven to very low, about 70c/gas 1. Dip the petals into the egg white, let them stick to the inside of the bowl briefly so that any excess will run off. Gently bury them in sugar then ease them out shaking off the excess sugar. Lay them on an oven tray lined with parchment paper and pop in the oven for 30-45 minutes, until crisp to the touch.
Turn up the oven to 200C/400F/ gas mark 6. Line the base and sides of a Swiss roll tin (33cm x 24cm) with a sheet of parchment paper.
Whisk the egg whites in a large clean with an electric mixer until they begin to firm up. Add the caster sugar in a slow stream, whisking, until you get a firm, glossy meringue. Use a large, metal spoon to fold in a teaspoon of vanilla essence, the vinegar and cornflour. Spread inside the lined tin and level with a palette knife. Pop into the oven and lower the heat to 160C/325F/gas mark 3. Bake for 30 minutes, until it is firm to the touch and crisp on top.
Gently tip out onto a piece of parchment paper. Carefully peel away the paper from the base. Now it’s ready to fill and roll up. Whist=k the cream until thickened and silky smooth, add the icing sugar Greek yoghurt and rosewater. Spread over the meringue, leaving a thin border around the edge. Dot the cherries all over, then roll up and carefully place on a plate. When ready to serve, dust with icing sugar and finish with the rose petals
Rose petals
The Meringue