I had some Lake Macquarie mullet yesterday, cooked properly by an old fisherman.
I was brought up in Bonnells Bay, which was a fishing village when I was a kid. There were about 10 professional fisherman and the whole waterfront had boat sheds that all belonged to coal miners from Cessnock who spent two weeks over Christmas living in the sheds. Most were built between the 1930s and 40s and were falling down when i was a kid in the 60s.
Anyway, mullet from Lake Macquarie tastes like mud if you just grill it and eat it. It has the flavour of the bottom of the Lake and is very oily as well. Despite that, old fisherman will eat it over any other fish, one because they could never sell it, and two, because they know how to cook it.
To cook it properly you fillet it and put it in a lunchbox or similar with a squeeze of lemon juice and a handful of brown sugar, then you shake the hell out of the box to get brown sugar to 'bind' with the lemon juice and oil in the fish.
Leave it for a while before cooking so the sugar disolves into the fish.
Cook it on a B-B-Q grill with the skin side down till it is just about cooked through, then turn it over for about 30 seconds so the sugar turns a bit crispy on the top.
You eat that between two thick slices of white bread and butter.
That is the best feed of fish i have had in my life, and i've tried everything I think. The only thing that tastes a bit similar, but not as good, is Tasmanian brown trout.