Well honestly that's about the fastest way. If you are in an FC that regularly feeds the chocobos that are stabled then you could just stable it.

Though I do highly suggest doing your Challenge Log every week to complete both companion challenges for the nice chunk of exp they reward you.

If you wish to stable your chocobo after that is complete (only if your FC actively feeds chocobos) or just continue killing level 49+ mobs with your companion out.

That's really about it.