Directions

1. Combine the rosemary, olive oil, mustard, salt, garlic powder, and pepper in a small bowl. Wrap the lamb bones with foil. Set lamb on a plate and brush rosemary mixture all over the meat. Cover and refrigerate 1 to 4 hours. Meanwhile, combine preserves and vinegar in a small bowl and set aside in the refrigerator.
2. Preheat a grill for both direct and indirect medium heat grilling (350°F to 450°F). For gas, leave one burner turned off. For charcoal, spread coals over only two-thirds of fire grate; the area with no coals is for indirect heat. Set the cooking grate in place.
3. Following the insertion guide on the Yummly Thermometer app, insert the thermometer horizontally through an end of the lamb into the meat until the metal is completely covered.
4. Starting with the bony side down, grill lamb over direct heat with the lid closed. Cook, turning once, until meat is browned, about 5 minutes. Transfer lamb to indirect heat with the meaty side up. Cook until the temperature of the lamb registers about 5° short of your cooking target, or about 125° and 15-20 minutes if you’re aiming for medium-rare.
5. Turn lamb bony side up (and return it to direct heat if you’d like the meaty side to be browner). Brush the top with some of the preserve mixture, cover, and cook about 2 minutes until jam is somewhat set. Turn lamb over, brush with the remaining jam mixture, and grill 1 minute longer. At this point the lamb should be at your target temperature (about 130°F for medium-rare), but if not, grill it a little longer over indirect heat. Transfer lamb to a cutting board and let rest 5 minutes before cutting into individual chops.