Preheat your Grill to 225F.
Remove the membrane from the back side of the ribs. Drizzle olive oil over both sides of the ribs and sprinkle rosemary.
In a deep baking dish, mix the potatoes with butter.
Place the rack of ribs directly on the grates of your grill alongside the dish of potatoes. Smoke for 3 hours or until the internal temperature of the lamb reaches 145F. During the last 20 minutes of smoking, add the asparagus to the potatoes to cook until tender.
Slice the lamb and serve with potatoes and asparagus.