Preheat the oven - Preheat the oven to 300°F (150°C) and line a baking sheet with parchment paper.

Whisk the egg whites - Using an electric mixer with the whisk attachment, whisk the egg whites on medium speed until soft peaks form. - Make sure your mixing bowl is clean and free of any grease, which can inhibit the egg whites from whipping to their full potential.

Gradually add the sugar - With the mixer still running, gradually add the caster sugar one tablespoon at a time, until the mixture is glossy and stiff peaks form. - Adding the sugar gradually will help the meringue hold its shape and prevent it from collapsing in the oven.

Sift in the cornstarch - Sift in the cornstarch and white vinegar, and fold gently with a rubber spatula until just combined. - Sifting the cornstarch helps prevent clumps and ensures it's distributed evenly throughout the meringue. Be sure not to over-mix at this step or the meringue will lose its structure.

Pipe the meringue onto the baking sheet - Scoop the meringue onto the prepared baking sheet and use a spatula or pastry bag with a star tip to shape it into a round or wreath-like form. - Don't worry too much about making it perfect - the charm of pavlova is in its rustic, homemade look. Make sure to leave a well in the center for the filling.

Bake the pavlova - Place the pavlova in the preheated oven and bake for 1 hour and 15 minutes, or until the exterior is crisp and lightly browned. - Don't be tempted to open the oven door during baking, as this can cause the meringue to crack. Instead, rely on visual cues to determine doneness - the pavlova should be firm and dry to the touch.

Let the pavlova cool - Turn off the oven and let the pavlova cool completely inside the oven with the door slightly ajar. - Allowing the pavlova to cool slowly in the oven helps prevent cracking or collapsing due to the sudden change in temperature.

Top with whipped cream, lemon curd, and fresh fruit - Once the pavlova is cool, top it with whipped cream, lemon curd, and a variety of fresh fruits. - Be creative with your fruit choices - any combination of berries, kiwi, mango, or pineapple would work well!

Serve and enjoy! - Slice the pavlova into individual servings and serve immediately, or store in the refrigerator for up to 2 days. - Don't worry if the pavlova cracks a little as you slice it - this is inevitable and adds to the charm of the dessert. Just be sure to serve it with a generous helping of whipped cream and fruits!