In the field, individual cans of beans are common, as are hard tack for the chunes, game meat jerky for the humans, and other sorts of foods that keep well. Foraging and hunting are also encouraged, so things like prickly pear or small game are common too.
In the headquarters, the cook tries her best to provide good and delicious meals for both the Chunish and Human populations with what she has available.
Local farmers grow beans and wheat, but the dry climate doesn't really lend itself well to lots of agriculture, so a lot of food is sent in by the railroad.
So if you live in Tacust, canned food is a major lifeline, and that's true regardless of what job you do.