What Is Christ-Centered Preaching, Really?

We have all heard that true Christian preaching must be Christ-centered (many of us have even read Chapell's book on the subject). But a question that we seldom ask is, How much Christ needs to be in a sermon for it to be considered Christ-centered? And if the answer is something like, "a lot," then the next question is, Can a sermon have lots of Christ in it and still not be Christ-centered?

Of course, some preachers in the PCA deny the premise that sermons need to be Christ-centered in the first place, so perhaps my first question ought to be about whether or not Jesus needs to be preached from every biblical text at all.

But I am curious to hear if any of you thinks that a sermon can be full of Christ, and yet not be Christ-centered. And if so, what would that look like?