We are in an Mediterranean climate that is semi-arid (fast becoming arid) and Cape gooseberries (phsyallis) works really well as a intermediate layer. In just 3 years, I've been able to breed seed that needs no water by starting with 10 plants in a harsh environment, and then just planting seeds from that area where I did no watering (two plants survived well
enough to give fruit). Blackberries also pretty hardy. But I feel like if you keep asking around, you might learn a lot more about what others grow locally.
Amaranth is very hardy and grows quite tall-- but even with no water can survive.
If
coffee a possibility? I'm growing robusta, as arabica doesn't do well close to the ocean-- but if you're in hills coffee might be good if you have some shade? Our robusta is surprisingly ...robust and resilient.
Natal plum can be a little picky about conditions, and is very slow growing. Kei
apple is a good option if you're looking for security, but the thorns are massive so keeping on the exterior of the planting space probably good. It's also very hardy and a great windbreak.
We also put large-ish medicinals like wormwood and pelagoniums.
All the different passiflora can survive with very little water once they're established (ie. if you can grow until quite large in a pot, then transplant...)
Roselle hibiscus? Here hibiscus is very hardy.
But I wish I'd asked around earlier when we were setting up our food forest, and not been as tied to specific
permaculture plants, as I think I had a lot to learn just from what people put around and about.