Preheat the oven to 120°C/gas mark ½. Line two baking sheets with baking parchment.
In a grease-free glass or stainless steel bowl, use an electric hand mixer to beat the egg whites until they form stiff peaks. Add the sugar, 1 tbsp at a time, and continue beating until the meringue mixture is thick and glossy. Spoon half the meringue mixture into another bowl and set aside.
Fold the rosewater into one half of the meringue. Dot the food colouring over the mixture, then gently fold to create a rippled effect. Sift the cocoa over the other half of the meringue and then gently fold through to create a rippled effect.
Spoon the pink meringue mix on to one lined baking tray in 3 large dollops and spoon the chocolate mix on to the other. Cook for 2 hours, then turn off the oven and leave the meringues in the oven for a further hour.