A whole leg of lamb is way too much for my family, so I've been happy to discover boneless leg of lamb steaks at the supermarket. The best are evenly cut slabs similar to beef steaks, but any cut of boneless leg of lamb will work.
I season the lamb and grill it. Meanwhile, I get the leeks and potatoes going on the stove. It's a much faster meal to prepare than a whole leg of lamb with roasted potatoes -- and it's just as delicious.
Note that the seasoned lamb needs to rest for at least 20 minutes at room temperature and up to 8 hours in the refrigerator.