I can't help you much with vegetables, but berries, especially raspberries, will grow and bear fruit in quite a bit of shade.

Australia is quite different from North America (which is all I know), climate-wise. Among other things, the sunlight is far more intense because of the latitude, so where I would need 8 hours direct sun, you may do very well with 4.

There is a dedicated Australian forum for edibles - you'd probably find the best advice there.

Here is a link that might be useful: Oz Edibles

If Raspberries do not need FULL meaning 6-8 hours of sun then I am doing something wrong becuase mine are not producing. My boss the green house owner told me full means 6-8. Some plants do ok with 4-6. Vegetables, will be slow to grow with less then six, so it woudl depend on the length of your season. Here in MN USA I have only 12-16 weeks so my tomatoes have to be in 6 to get anything. A local greenhouse would be most helpful for what your climate will sustain.
Good-luck,

Lettuce might work especially the kind you can cut the individual leaves off, not head lettuce. I read to start the seedlings in more sun (so they will grow faster) then wean them into the more shade area. Broccoli might do with less sun too.