Heat the oven to 150C/130C fan/gas 2 and line a baking tray with baking parchment. Put the egg whites in a large, clean bowl along with a pinch of salt, and whisk using an electric whisk until white and billowy – they should be doubled in volume. Add 200g of the caster sugar, a spoonful at a time, whisking continuously. When the sugar has been fully incorporated, whisk for another minute until the meringue is thick, glossy and holds stiff peaks.

Dollop spoonfuls of the meringue onto the baking tray using a large metal spoon, spacing them out evenly (you should get about six in total). Bake for 1 hr, then turn the oven off, leaving the tray inside for at least 1 hr to cool. Once cooled, remove from the oven and set aside. The meringues will keep in a sealed container for up to a week.

Heat the oven to 200C/180C fan/gas 6. Arrange the rhubarb in a roasting tin, sprinkle over the remaining 50g sugar and tip in the orange juice. Roast for 15 mins until the rhubarb is tender. Pour the roasting juices into a saucepan and simmer over a medium heat for 5 mins until syrupy. Leave the rhubarb and syrup to cool, then chill until you’re ready to assemble. Can be prepared two to three days ahead.

Pour the cream into a large bowl with the icing sugar and rosewater. Whisk until softly whipped, then gently fold through a drizzle of the rhubarb syrup.

Crush a few of the meringues over a large platter, then dollop over spoonfuls of the whipped cream. Spoon over the rhubarb, then add another layer of crushed meringues, whipped cream and rhubarb. Drizzle over any leftover syrup, then scatter over the pomegranate seeds, pistachios and crystallised rose petals, if using.