Fish

Give a man a fish, and he'll eat for a day.

Teach a man to fish, and he'll eat for a life time.

But where does he get the fishing pole?

And the bait?

And the lures and boobers and hooks and line?  Tackle box?

And what happens if that fishing pole unexpectedly breaks?

And this is all assuming he lives near a river in the first place.  One that's not saturated with upstream factory pollution or choked by algae.