With much of it unsafe or unpalatable raw, a variety of methods were employed to render the various foods edible, such as cooking on open fires (meat) or boiling in bark containers. They would pound vegetables and seeds, or hang them in bags in running water.[

Many foods are also baked in the hot campfire coals, or baked for several hours in ground ovens. “Paperbark”, the bark of Melaleuca species, is widely used for wrapping food placed in ground ovens. Bush bread was made by women using many types of seeds, nuts and corns to process a flour or dough.

https://en.m.wikipedia.org/wiki/Bush_tucker