To reduce aquafaba, pour it from a can of chickpeas into a saucepan and simmer over medium heat, stirring occasionally. Allow the liquid to reduce by about half until it reaches a thicker consistency. This process usually takes 10 to 20 minutes.
Once thickened, remove from heat and let it cool to room temperature, as it will thicken slightly more as it cools. You can then use it immediately or store it in an airtight container in the fridge for up to 2days.
Preheat the oven to 230°F (110°C). Lightly grease 2 -3 baking trays with oil and line it with parchment paper.
In the bowl of a stand mixer, add the reduced aquafaba and whisk on medium speed until soft peaks form. Add the cream of tartar, xanthan gum, and salt. Increase the speed to medium-high and continue whisking.
Gradually add the cane sugar, a quarter cup at a time, while whisking until the mixture forms thick, glossy, stiff peaks. Sift in the cornstarch and add the vanilla extract. Whisk for another 30 seconds to combine.
Prepare a piping bag fitted with a star nozzle and fill it with the pavlova mixture. Pipe 2 1/2-inch-wide circles or nests on the prepared tray as shown in the video (link). Use a spoon to create an indentation in the center of each nest to make room for the cream.
Bake the pavlovas for 2 hours, then turn off the oven. Leave the pavlovas to cool inside the oven with the door closed. The outside should be crisp and dry.
Once cooled, store the pavlovas in an airtight container for up to 7 days.
Before serving, add a dollop of freshly whipped cream to the center of each pavlova. Top with a generous spoonful of lemon curd, fresh blueberries, and a dusting of powdered sugar.