We came across a short article in the yottie press a few years ago which explained how to keep meat without refridgeration.
Basically, the meat (marinated previously if desired) is fried in olive oil, allowed to cool, then transferred to a clean jar that can be sealed tightly. The cooking oil is added, and the jar is topped up with fresh oil and then sealed. Apparently it is important to use non-metal implements for cooking and transferring. To serve, the meat is just heated through in a frying pan with some of the oil.
We tried this with some lamb and it kept for 6 months with no problem. Presumably this would also work for fish such as tuna.