Another picture

The tree

Looks like an Australian native called Pittosporum undulatum. If I remember correctly the flowers smell citrusy but I would definitely not eat it. It's indigenous to the Sydney area but grows like crazy that its ended up on a lot of council weed lists.

The fruits and leaves look pretty close.

Here is a link that might be useful: Wiki

That's definitely it, thanks gooooone ! No wonder I couldn't find it anywhere. I was hoping it was some kind of 'quat relative with some edible value. Glad to know what it is, thanks. It certainly throws out enough seeds, can see how it could be considered invasive.