I started with this recipe, then started tweaking.
The store had no stewing lamb, but they had shoulder blade chops on sale. So I ended up using 1lb of stew beef and 8/10 lb of the lamb shoulder, carved off the bone and chunked.
They also had no shallots, so I used scallions instead.
Used dark amber beer instead of beef stock.
Added a couple of glugs of shiraz in addition to the red wine vinegar.
Didn't drain the tomatoes before adding.
Used a bag of baby potatoes, halved or quartered, rather than regular or red.
I ended up with a much more Italian stew than "Greek", but it is definitely le tasty. I think next time I'll dredge the meat before browning it, as adding thickening towards the end necessitated some last minute re-spicing (alt, pepper, garlic) and dredging would probably eliminate that need in the start. But other than that, I count this as a win.