Preheat your oven to 225°F (107°C) and line a large baking sheet with parchment paper.

In a large mixing bowl, beat the room temperature egg whites until soft peaks form, gradually adding sugar and beating until stiff peaks form.

Gently fold in lemon juice, vanilla extract, and cornstarch to the meringue mixture.

Pipe circles of the meringue mixture on the parchment paper, creating a small hollow in the center of each.

Bake the meringues for 1 hour and 15 minutes; then turn off the oven and leave them inside for an additional 30 minutes to cool.

Whip the cold heavy whipping cream with sugar until soft peaks form.

Once cool, fill the centers of the pavlovas with whipped cream and top with fresh fruit and mint if desired.