Instructions

1. For the pavlova: pre-heat the oven at 160 C, line a baking tray with baking parchment. Draw a circle size of a small plate.
2. In the clean mixing bowl add the egg whites and whisk with an electric whisk ( I used a handheld, works just fine too) until soft peaks form when the whisk is removed. Gradually add the sugar a little at time, whisking at maximum speed until they are stiff and glossy. Mix the corn flour and vinegar in a cup till smooth and stir into the egg whites.
3. Spoon the meringue onto the baking sheet and smooth the edges into a round dome. Flatten and concave slightly the top so it can hold the curd later.
4. Reduce the oven temperature form 160C to 140C and bake in the oven for 1.5 to 2 hours. Switch off the oven and leave the pavlova overnight (or a few hours at least) to cool and dry. 
5. For the lemon curd: mix the lemoncello, lemon zest and juice with the corn flour add stir to form a smooth mixture. 
6. In a mixing bowl add the sugar and egg yolks and whisk till pale. Reserve.
7. Boil the water in a non stick pan, add the lemon corn flour mixture and stir over the heat until it thickens and remove from heat. Add the sugar and egg yolk mixture and whisk it in, add back onto the heat and stir for a few minutes. Set aside off the heat to cool slightly before serving.
8. To serve: add to the whipped cream a few table spoons of lemon curd,  layer on top of the cooled and dried pavlova, add a few slices of lemon for decoration.