Steam also really preserves nutrients well. Although in a pure survival situation if food is scarce it might be best to stick with the one pot never ending soup. Pretty much 100% efficient, although would get extremely boring after a couple weeks. And you need a cinstant source of heat.
"Women however should get a spanking at least once a week by their husbands and boyfriends - that should be mandated by law" - Zelcorpion