This was sooooo gooood!!! I have never thought of using a lemon curd with sour cream to top a pavlova but it works wonderfully and tastes gorgeous.. All my guests raved and this will definitely be made again and again. I did up the egg whites used as I wanted to make a larger meringue so there was enough for all my guests. I also did not make an indentation in the top of the meringue to spoon filling in, as I did not want to chance it caving in like you mentioned. So I just spread the mixture over the top and then topped with a mix of fruits including kiwi, strawberry, blueberries, passion fruit etc... It looked so pretty and really did taste so good. Thanks for sharing such a great recipe a real winner both in taste and presentation.