Love everyone elses suggestions - the only other things I can suggest is:
Balsamic vinager & brown sugar if the onions arent' already caramalised with it.
If she does use those to caramalise the onions and it's still not sweet enough to match the feta, add semi dried tomatoes or beetroot.
If it's the mouth feel try adding just a little bit of beaten egg and cream, or grate a little softer style pecorino cheese on the top.
If you can find Lauraine Jacobs blog, she has some amazing recipes on there.
_________________________
"While it may not pay to be different, who can really afford the price of being the same?"
DS 9yrs, DS & DD 5yrs, DD 4yrs
Plus 9