One such example, is how to smoke and preserve meat using only sticks, firewood, and a blanket. The video below, courtesy of the James Townsend & Son YouTube channel (aka Townsends) shows a very easy to master system for smoking and preserving meat.
Afterwards the dried/smoked meat can be stored in a dry place for weeks or even a month and still be good to eat. It can also be added to soup, stews, and other foods.
This also ends up being an excellent survival method of preserving food when living in the wilderness for months at a time.