Option #2 (harder, looks like the photos in this post): Use a pastry bag fitted with a very large circle tip. Starting in the center of the pavlova, pipe one line out to the edge of the circle. Start right next to the other line at the center and do it again. Continue this until you have a starburst pattern and have filled the circle. Now, do it again on top for a second layer, but don't go all the way to the edge of the circle, instead stopping about 1 inch short to allow the 1st layer underneath to show. Use the back of a large spoon to make a small bowl shape that's about 3 or 4 inches in diameter across in the center of the pavlova to allow space for the toppings later on.
Place 1 or 2 inches of water in the bottom of a double boiler. Bring the water to a boil over high heat, then reduce the heat to low and place the upper pot on top. Add the passionfruit pulp, lemon juice, egg yolks, and sugar and stir with a whisk to combine. Continue gently stirring as the mixture cooks (this will prevent the egg yolks from curdling and keep the nice smooth silky texture of the curd). Eventually the mixture will thicken enough to coat the back of a spoon, (it will take about 10 minutes or so depending on the heat of your stovetop).
Place the whipped cream on top of the pavlova in the center, spread it out into a small circle. Add the curd on top of that, a spoonful at a time, until the desired amount of curd is added. Cut all the fresh passionfruit in half, scoop out the pulp of two of the passionfruit and drizzle it over the pavlova. Place the remaining halves cut-side up on top of the pavlova, sprinkle with the blueberries and chopped pistachio, and serve.