Instructions

1. Cook the beans before they go anywhere near the machine, and rinse them well. Drying raw beans achieves nothing — they have to be edible first, because all the machine does is take water out.
2. Spread the cooked beans one deep on a lined tray and run them at 71 °C for 6 hours. They are done when a bean is hard and wrinkled and rattles on the tray; anything still leathery will not come back evenly in camp.
3. Dry the cooked chicken on its own tray at the same setting, shredded rather than diced. Shredded meat has far more surface for its bulk and rehydrates to something tender, where a dried cube of chicken stays rubbery whatever you do to it.
4. Spread the salsa thinly on a solid sheet and take it all the way to a brittle leather, then crumble it. A salsa sheet left soft folds moisture back into the bag and is the usual culprit when a camp meal goes off.
5. Combine the beans, chicken, salsa crumb, instant rice and the four spices in a bag only once everything is stone cold. A single warm component sweats and dampens everything packed beside it.
6. In camp, add water to just cover, stir once, and leave it sealed in a cosy for about fifteen minutes. The rice sets the timing; the beans and chicken will keep taking up water for as long as you give them.
7. Check before you drain anything. The rice should be soft and the beans should give under a spoon, and if they do not, add a splash more water rather than draining and finding it dry two minutes later.
8. Spoon the filling into the tortillas and scatter the cheese over while it is still steaming. The residual heat is as close to melting as you get away from a stove, which is why the cheese goes on last.
9. The dried components keep six months bagged airtight and cool. The tortillas and the cheese are the short-life items in this list, so buy those for the trip rather than storing them with the rest.