Glad the food came through in the end, and thanks for the detailed report! It looks like the beef has changed since I last rode long distance in 2016 - here's what I got then:
It was actually quite good, in my opinion - obviously not fresh, but better than I might have expected.
I've also encountered the partly frozen cold portion. I've found that it pays to go straight to the dining car shortly after boarding to introduce myself and make sure that the service attendants know what I need. If nothing else, they seem to get no information on which item I ordered for each meal, so I have the chance to tell them what I want when. (Not that they always remember correctly - I was once served the beef for breakfast by mistake, except that Borenstein also got it wrong and it was chicken. But that train had unusually bad staff in the dining car.)