I've frequently found Sahar II to be out of ground lamb and offer the half leg. Has anyone actually gone there and found ground lamb?
Typically I only need a pound or two, so buying large quantity of meat is unappealing.
The Lebanese Meat Market on Kedzie is an option, but I've found you just can't stop in there and expect them to have what you need. Shoulder chops go quickly and they may just have primals which they are not interested in breaking down if you just walk in. I haven't stopped in there just for ground lamb, but I imagine they can accommodate you. But I don't go there now if I don't call ahead.
There is a ground-to-order halal butcher on Devon that I often stop at if Kedzie isn't the answer. I believe it's this one:
Chicago Zabiha Halal
2243 West Devon Avenue
Chicago, IL 60659
(773) 743-6934
It is very popular on the weekends (usually a good sign) and I recall pricing was more in the $3-$4/lb range. They move a lot of ground lamb.
Sometimes I'll pick it up at Whole Foods or Mariano's/Whole Foods and pay the higher prices if I don't want to go out of my way. Good tip about Treasure Island.
I, too, wholly attribute any rise in popularity to the Jerusalem cookbook.