To start with and especially looking to MM for information...
As my partner and I, still have the methods of preparing meals from the time of the Fifties-Sixties...

One question perhaps solved after more than 70 years ?...

My mother from East-Flanders, my father from West-Flanders (both of the former County of Flanders)
My partner from West-Flanders, me from the two...

My mother prepared apart "string beans with applesauce" for her and for me and my sister.
My father prepared apart for his own: "string beans with baken hacked onion"

After some initial trouble I prepare now my father's recept for me and my partner and add than for me alone applesauce. And sometimes the partner adds soft? mustard and so do I even with the applesauce. And I personally find my "concept" a tasteful blend ...

I did some research this evening on the mighty google, but I hadn't that many hits with "string beans with applesauce" (snijbonen met appelmoes)..only for pregnant women and as "vermageringskuur" (that word don't seem to exist in official Dutch?) (treatment for losing weight?)...

And nevertheless my mother had a name for her recept in her dialect: "bonen (beans) met "sleutsekes" (peulen? (pods) met appelmoes (applesauce)" as proof that it really was a kind of preparing in the region around Ghent and I suppose in Ghent too...