Grapefruit and pomegranate pavlova

Making the mango insert
Preheat fan oven to 180°C.
Whisk the egg whites with an electric mixer on a low speed then gradually add the caster sugar. Increase the speed slightly then, when the mixture is shiny and very thick, add the white vinegar and the cornflour, and continue for a few minutes.
Place the meringue in Le Tube fitted with a fairly wide fluted nozzle, and adjust to the 5 cl (50 ml) position.
Lay baking paper on a baking sheet then draw two 10 cm circles with a pencil. Turn the paper over then cover the inside of the circles with Le Tube 3-4 cm thick, so as to form a small well in the middle.
Bake for 1 hour 15 mins, then cool for at least 2 hours in the oven, without opening the oven.

Making the garnish
Peel the grapefruit and remove the segments.
Take the seeds from the half-pomegranate.

Making the whipped cream and decoration
Mix the mascarpone using a spatula to loosen it.
Pour the cream into the bowl of a food processor and add the mascarpone. Start whisking slowly and gradually increase the speed. When the cream becomes thicker, add the icing sugar. Whisk until you obtain a stiff whipped cream.
Place the cream in Le Tube fitted with a plain nozzle and adjust to the 5 cl (50 ml) position. Pipe the cream over the meringues.
Place the grapefruit and pomegranate segments on the pavlovas. Add edible flowers to make the dessert look attractive (optional) and eat immediately.