Complete each set of the Shado-Pan daily quests without a Shado-Pan companion or leaving Townlong Steppes.
There are three sets of Shado-Pan daily quests:
You must have the Choose a Shado-Pan Companion debuff while handing in the quests to satisfy the achievement's criteria. You will lose this debuff upon leaving the zone. To reacquire it, you must first abandon one of the quests and then reaccept it.
Each set of daily quests offer an additional quest after the completion of those that are initially given. You'll receive credit after turning this quest in.