Step 1: Preheat your oven to 250°F (120°C) and line a baking sheet with parchment paper. Draw a 9-inch circle on the parchment as a guide.
Step 2: In a clean, grease-free bowl, whisk the egg whites and cream of tartar on medium speed until soft peaks form.
Step 3: Gradually add the superfine sugar one tablespoon at a time, whisking on high speed until the meringue is thick, glossy, and the sugar has completely dissolved.
Step 4: Gently fold in the cornstarch and white vinegar using a spatula, being careful not to deflate the mixture.
Step 5: Pile the meringue onto the parchment circle, using a spatula to create a slight well in the center for the citrus pavlova recipe filling.
Step 6: Bake for 90 minutes, then turn off the oven and let the pavlova cool completely inside with the door slightly ajar for at least 3 hours.
Step 7: Once cooled, whip the heavy cream to soft peaks. Spread the cream into the center of the pavlova.
Step 8: Swirl the lemon and orange curds over the cream and top with fresh citrus segments and mint before serving.