Bron,
if you can, next time ask the butcher to remove the bone. You can use the bone to make soup, and the roast shoulder boneless, is absolutely superb.

I purchase lamb shoulder in bulk, get the butcher to take out the bone and i then cut it up into casserole pieces and freeze them. Front shoulders are the best of a lamb i reckon.

Yummo!

What i do, is season it, marinate it in some home made tomato/capsicum paste for 1-2 hours. Put in oven baking tray, thickly slice onions, cut potatos into quarters, cut pieces of pumpkin. Mix tomato/capsicum paste with water, add to tray (to about half of the height of the lamb), cover with foil and roast for about 2-3 hours.

mmmmm

Make some pilaf. Tzaticki too, green salad and Enjoy