Hi Josh, welcome to Ausfish.
Mate, mullet are an excellent fish to target! Can be quite tricky, sometimes difficult to hook.
I am envious of you having that resource available, they are great fighters and make excellent bait!
Used to fish for them in Queenscliffe Lagoon in Sydney about 45 years ago,
used stale bread for burley, a combination of bread, flour and cotton wool all mixed up with a bit of water into a thick paste for bait.
Very small hooks (size 8-10) under a very tiny split shot (or no sinker if you can cast far enough without using one), about 20 - 30 cms under a small piece of white coolite foam used as a float. Line about 3kg is plenty strong enough. Very similar to a river gar rig.
Not completely sure if the fellas you are chasing will respond to this approach, but if they attack stale bread broken up and used for burley on the surface, you should be right. Just cast your rig into the burley and wait for a hit!
I'm sure other members will offer some useful advice.
Have fun Josh, nice looking flatties as well!