Eggs are best, have lots of vitamins and minerals, are very cheap and avilable, easy to clean up, lots of varieties, long-time refrigerator storage, and quickly fix in so many tasty ways: hard boiled, soft boiled, 2-minute, egg salads, scrambled, egg sandwitches, bacon/ham and eggs, filling for tortillas, deviled, fried, microwaved, over-easy, mixed with favorite spices, etc..
Raising chickens is a good way to survive on a subsistence life style. Chicken should be the national bird in the U.S..