Maybe you think of the Father, Son, and Holy Spirit. That’s cool, I’m with you. Good answer.
Maybe you think of the girl from The Matrix. That’s weird, I’m not really with you. I’m surprised your mind went there. You’re probably a Keanu Reeves fan and I’ll pretend like you never brought it up.
Maybe you think of mirepoix. Ok, probably not. Maybe you don’t even know what mirepoix is, but that’s what I’m thinking of. Mirepoix, sometimes referred to as the holy trinity of French cooking, is an equal combination of onion, celery and carrots. Most commonly used in American Meatloaf, chicken soup of any kind, and even pasta sauce!
Wikapedia - http://en.wikipedia.org/wiki/Mirepoix_(cuisine)