Place the pan in the oven and allow to cook for 15 minutes.Remove and turn the lamb over. Cook for another 10 minutes for medium-rare, 15for medium. Use an instant read thermometer to check the doneness. If the temperatureis not to your desired doneness, cook for another 2-3 minutes at a time.*
Optional: to give the bones a clean look, use a paring knife to trim off the excess membrane between the bones down to where the meat starts. Do this as the first step.
* Doneness Temperature Chart