Rock means you can grow things other people can't.
But I assume you have clay or adobe on top?
Almonds? Pistachios?
Short, but implies Persian/English Walnuts should be good:
http://homeorchard.ucdavis.edu/backyard-climate.pdf
Macs probably need a lot of water:
http://www.crfg.org/pubs/ff/macadamia.html
[ snip]
Waimanalo
M. integrifolia. Originated at the Hawaii Agricultural Experiment Station, Waimanalo, Hawaii. Large nuts, occasionally with twin halves. Shell relatively thick. Kernel 38-1/2% of nut, flavor good, oil content 75%. Tree medium-sized, pyramidal, productive, begins to bear after 5 years. Produces nuts in large clusters. Resistant to frost and disease. Grows well in cooler climates, particularly near the ocean. Also yields good crops inland.

http://www.crfg.org/pubs/ff/edible-palms.html