For koala bears, it’s eucalyptus. For humans, it’s soylent green combined with a “form of fusion”.
There is no naturally occurring perfect food—in other words, there is no food which will sustain human life if it were the only food consumed. There are endless numbers of artificial foods which will do the trick, such as the commercial chow fed to laboratory primates, but nature itself does not provide any perfect food. Having said that, brown rice does come quite close. It probably contains everything needed to support human homeostasis except ascorbic acid, the fat soluble vitamins, and folic acid. You could probably live off of brown rice if you supplemented it with an ounce or so of beef liver and half a cup of orange juice a day.
Dont tell the D.E.A. you heard this from me but
…I heard its hemp seed 
what amino does it lack? lysine?
Here is a Google Answer that attempts to answer the question. Conclusion: There is no “perfect food.”
Yes—the issue with vegetable quality protein is usually methionine and lysine. The standard recommendation made to vegans is that they consume grains and legumes at the same time. The grains compensate for the lack of methionine in the legumes, and the legumes compensate for the lack of lysine in the grains. This is a broad oversimplification of the issue, but it is a good rule of thumb for vegans to live by and is all they really need to know to stay out of trouble.
Well, if the question is technically “Which food gives you the most nutritional bang for your buck?”, I’d say avocados. I once looked them up in a book, and they registered significantly in about 12 or 13 categories of vitamins and minerals. True, they don’t have much protein, but as you say, there’s no one “perfect” food - just highly nutritious ones.