Well, yeah - it’s not like the Kitchen Police would stop me if I tried it - but I was wondering if anyone else had had the notion and possibly put it into practice.
If you’re totally goy I expect the fat used to make the dumplings doesn’t matter. I suppose if you’re angling towards kosher style you could use rendered beef fat.
My sister gave me a couple of boxes of matzoh ball mix that came with a “soup packet” that was supposed to make the broth to cook them in.
As near as I could tell, there was nothing in that packet that had ever been near a chicken (or any other animal, for that matter, with the possible exception of a human harvesting parsley.) It seemed to be mostly MSG, salt, and spices. I tossed it out and made some chicken soup to cook the matzoh mix in (the mix itself seemed fine.)
I’d think they’d taste a bit different if you cooked them in beef stock, and different yet if you used lamb, but I don’t see why it wouldn’t work. Try it and let us know!
Think I’ll give it a try this “weekend” (my days off usually fall between Monday and Thursday, they move around between those) and let you know how it goes.