What are the minimal chemical requirements for a food which we all can eat?
Considering the three basic biomolecules used by the body are carbohydrates, lipids, and proteins, you would need to consume these three molecules only. Now we can choose three substances.


Glucose, one of the most basic carbohydrates, is needed for ATP production, so that would be a food choice there.
Any oil or butter will provide lipids.
Protein comes from a variety of sources. Meat is typically though of as the best, but nuts are a pretty good source too.


Since nuts satisfy proteins and lipids, I'd say honey roasted peanuts are the most basic food you could live off of, if you replace pure glucose for the honey.