Prep: 1. Preheat oven to 425°F. 2. Mince garlic and chop thyme. Make: 1. Whisk together mustard, garlic, and thyme. 2. Sprinkle lamb with salt and pepper to taste. 2. Place lamb on a roasting rack, rounded side up and spread mustard mixture evenly over lamb 3. Roast lamb until thermometer inserted into center registers 130 to 140 degrees F for medium rare or 140 to 150 degrees F for medium. Will take 30-45 minutes: check periodically. 4. Garnish with thyme sprigs, if desired.
For a slight variation, after spreading on the mustard mixture, coat the lamb with 1 cup of breadcrumbs pressing them on gently to help them stick.