I use shoulder or leg for roasting, I prefer bone-in as the bone acts as a heat conductor and adds to the flavour. I use the same method as brisket. I like to cook lamb with white wine, not red. Herbs that go well with lamb are thyme, oregano and rosemary. My go-to condiment for lamb is redcurrant jelly, dijon mustard is also a good accompaniment.
When a recipe calls for pink or medium cooked lamb, I opt for a french trimmed rack. I wrap the bones individually, in foil and then sear the lamb on all sides in a hot pan with a splash of olive oil. Roast in the oven, until cooked to your liking. Use a thermometer. Rest the meat and remove the foil before slicing or serving. You can leave the rack whole if you like, trendy restaurants serve it as ‘2 bone chops’.