[dflock]

Probably: rice, wheat, cassava, potato, banana?

You obviously need to eat some other stuff occasionally, but those plants are the staple diet for a large chunk of the world population.

[twothamendment]

It is old, but potato alone will get you pretty far: https://www.livescience.com/10163-man-eating-potatoes-2-mont...

I'd need some variety just so I didn't go insane.