It may be "messy" but it's worth every bite!
Preheat the oven to 100C.
Separate the egg whites from the yolks. Keep the yolks for another use. In a stand up mixer, whisk the egg whites until stiff. Gradually add the sugar, a tablespoon at a time until each addition has dissolved before adding the next one. Once the full amount of sugar has been added and the meringue is thick and glossy, continue to whisk, and add the cornflour, then the vinegar. Whisk to combine. Line baking trays with baking paper, and using a sieve, lightly dust cornflour over the paper (to prevent them from sticking).
Transfer the meringue into a piping bag with a plain 10mm nozzle.
Pipe meringues into 4cm domes onto the trays, making sure there is at least 3cm between them. Sprinkle with pistachios and place in the oven. Bake for 1 hour, or until crisp.
Meanwhile, make the blueberry compote. Place the blueberries, sugar, lemon and water into a deep saucepan. Bring to a simmer and cook for 5 minutes covered, or until the blueberries have softened. Remove from heat and set aside to cool.
To make the candied orange, zest the oranges with a wide peeler. Slice the peel finely into thin matchsticks. In a large saucepan, add the sugar and water and simmer until the sugar has dissolved. On a low heat, cook the sliced orange peel in the sugar syrup for 15 minutes, or until the peel is tender.
Drain the orange peel and transfer to a lined baking tray, spreading the peel apart as much as possible. Toss the peel through ¼ cup of sugar so that the peel is completely coated. Keep in an airtight container until needed.
Whip the cream and set aside.
To assemble, place 2 meringues in the bottom of a jam jar, cover with a tablespoon of whipped cream, blueberry compote and a small handful of fresh blueberries. Repeat the process with 1 more meringue and finish the desert with a garnish of candied orange, and a sprinkling of ground pistachios.
Serve immediately and enjoy!