Weigh out your ingredients at the start to make it a little easier to prepare.
Line a baking tray with baking parchment and draw a circle of the desired size you wish the final meringue to be. I used a 20cm (8inch) base of a springform pan to draw around, a plate also works.
Meringue: In a large clean mixing bowl or stand mixer, whisk the egg whites until they start to form soft peaks.
Keep mixing and gradually add the sugar a tablespoon at a time, allowing the egg whites to incorporate the sugar slowly and remain stable. If you add the sugar too quickly the egg whites will collapse.
Once all the sugar is added, continue whisking until the egg whites form stiff peaks (holds its shape when pulling out the whisk) and the sugar has dissolved (rub a little of the mix between your finger and thumb and you should not be able to feel any sugar grains).
Whisk in the lemon juice, vanilla and cornflour.
Preheat the oven to 130°C fan / 265F / Gas 1/2.
Spoon the meringue into the centre of your drawn circle and smooth it out into a cake shape. An optional extra is to pipe some small meringues to decorate: Use a star nozzle to pipe 6-8 small meringues onto some baking paper. Place them in the oven when the large meringue only has 30 minutes remaining to bake. Use a small pallet knife or spoon and draw up at an angle from the bottom edge to the top. Work your way around the outside edge until you have gone all the way around.
Baking: Place the meringue on the middle shelf and then turn down the oven to 100°C fan / 212F / Gas 1/4 for another 90 minutes.
Once baked, turn off the oven and leave to cool inside for 40 minutes. Then remove and leave on the side to cool completely.
Decoration: Whip the cream until you get soft peaks. Once the meringue has cooled, gently tap around the centre to create a hole. Fill the hole with some of the fruit and then top with the whipped cream. Finally, add the remaining blueberries or blueberry compote and serve.If you are using fresh fruit you can also dust with icing sugar before serving. Optional blueberry compote: In a small saucepan bring half the blueberries to a boil with the 1 teaspoon lemon juice and 1 tablespoon maple syrup. Let it boil for 3-5 minutes and then remove from the heat to cool. Once cooled, I like to blend the blueberry mixture to make a nice sauce which I then add my remaining whole blueberries to. Leave to cool and then spoon over the cream.