I think I know the answer but I'll throw this out for comment as I'm hacking and tweaking my morning routine:
Though cutting beef chuck into small pieces is slimy and disgusting when raw, it seems to cut much nicer than when it's cooked (especially trying to cut it when hot).
Despite me having invested in a really expensive and fancy cutco knife set, when hot, it tends to shred and not cut well. I've also tried "chopping" which works maybe a tad better, but still not ideal.
I suppose if I let the beef chill in the fridge it would cut better, but I'm trying to squeeze a pressure cooker pot roast into my morning routine before work (yes, pretty ambitious I know :-)
So, as I type this, I guess the answer is clear: cut it raw: that way it will cook faster and the results will be nicely cut pieces.
Just thinking out loud,