I thought I could pepper my response with a condiment - ketchup.
Hadn't I already figured it out? It was something of a marketing term. Maybe just an artful name attached to a recipe. With a condiment like catsup, you were able to please the most sophisticated palate. Grabbing a bottle of ketchup sauce, one could never go wrong! If you were out of time and unable to prepare a gourmet meal, with this sauce you instantly "catch up" and the dinner would be saved!
Well, maybe not ... this wordsmith doesn't even mention the possibility! World Wide Words
After all this time of laboring under a misconception, catchup isn't catch-up???