Lamb shoulder roasts are a great candidate for slow roasting. Roast on top of sturdy veggies like sweet potatoes and carrots for a tasty side dish.
Braising low and slow or pressure cooking are other great methods for preparing these roasts.
A recipe that uses lamb shoulder is Easy Lamb Chili Verde. We have been experimenting with substituting lamb shoulder in recipes that generally use pork shoulder and finding it is a great substitute. We recently made BBQ pulled lamb and it was amazing.