Sorry to catch your thread a bit late Benen.
I'm an Adelaide boy too, I've been bushwalking for many years in SA and elsewhere.
To be honest, I wouldn't be too concerned about cooking in the rain. It very rarely happens that its actually raining in South Australia when its time to cook! Especially the further north you go, number of rain days is very very limited. I can only actually think of a couple of times when there has been some rain around whilst we've been cooking in camp in SA-and bushwalking season is over winter. Few tips to make it more bearable when it does happen, without having to carry extra equipment for the (rare) time it happens...
...obviously wear your jacket (and rain paints if you use them...we never carry those though)
...camp in a sheltered position, cook in a sheltered position. This is obvious, but sometimes its overlooked or not thought about. It can make a big difference to how warm, dry, calm it is in camp. On a side note, the same goes for when you have rest breaks.
...one of you can be in the tent, preparing food and doing tasks to help the person outside, while the other is outside cooking. Teamwork always speeds things up.
...cook in the lee/underneath a tree. Native pines in the Flinders probably have the thickest canopies. River red gums can be good too down in gorges, though be careful to avoid them in high winds and never camp underneath them as they drop branches.
...just be efficient about cooking. Once you get more experienced packing your pack and pitching camp, using your stove set-up and cooking on it, you'll find that you aren't outside cooking for very long anyway.
...often you can get your meal almost cooked, then cover it in a lid and warm jacket (careful not to melt anything) and bring it straight in the tent, allowing you to put out your stove and get inside sooner. The warmth left in the pot and food will finish the job.
...I'm sometimes lazy and leave some things outside in the rain, like my pots, stove, water bottles/bladders, etc. Meh, animals aren't really a problem just about anywhere in SA (watch for Ants).
...Once you get more used to it (and if you are careful about fire safety and ventilation) you can cook carefully in your tent vestibule. Keep it as clear as possible, be really careful with lighting and fuel leaks, etc. This is common practise by bushwalkers in the snow, in bad conditions in Tasmania (pretty common there...), etc.
Good luck :-)