Knight Endgame Lesson - Back to the Basics

Reviewing your games with a strong human player is the best way to get a “second opinion” about your chess skills, much better than doing it with a computer engine. Here is one example that was shown to me, that illustrates the power of basic strategic components such as distant passed pawn in knight endgames.

Lai – Jiganchine, 2012
 Black to move. Find the best move/plan (feel free to post it in the comments section).
Hint: Black wants to a create a passed ‘a’ pawn.