Mix in a mixer egg whites with powdered sugar until thick foam
Add corn flour and vinegar to egg whites. Mix everything thoroughly
Lay out the resulting mixture with a spoon on a baking sheet, forming 4 "nests". Bake for 45 minutes at 300 F / 150 C
Add sugar, orange juice to the yolks and mix everything. Put on a water bath and stir constantly until the mixture begins to thicken
Pass through a sieve orange curd and add butter. When the orange curd has cooled, fill the pastry bag with it
Fill Pavlova cakes with orange curd (you can add caramelized orange and orange jelly). Bon appetit!