rice is usually the No.1 in UN relief operations. Cheapest per energy benefit, long shelf life, dense storage. Also lentils, chickpeas, any other of the hard vege pellet types. keep in mind these need fuel . if cooking and heating becomes expensive, cold soaking can speed it up. Other grains and cereals may need less energy to prepare.
For protein, eggs and chicken stay the most affordable in poor countries I have seen. Also offal, a favorite of our ancestors. Beef and sheeps heart are veru nutritious and fry up like normal steak. Kidney and liver if you like them. Pigs feet, pigs head( quite a bit of meat on a pigs head), gel brauns, fish head stews. Also all the less popular fishing options. Catfish, eel, baitfish, squid, ray, shark, whatever you have in your region.
Catfish is very popular fish around here.
