- 2 tablespoons coarse dry breadcrumbs, preferably whole-wheat (see Note)
- 1 1/2 tablespoons extra-virgin olive oil, divided
- 1 teaspoon chopped fresh rosemary, divided
- 3/4 teaspoon kosher salt, divided
- 1/4 teaspoon freshly ground pepper, divided
- 1 (1 1/2) pound rack of lamb, Frenched and trimmed (see Tip)
- 3 teaspoons Dijon mustard, divided
- 2 shallots, finely chopped
- 1 (15 ounce) can lentils, rinsed
- 1 Granny Smith apple, finely chopped
- 2 stalks celery with leaves, finely chopped
- 3/4 cup reduced-sodium chicken broth or water
- 2 teaspoons sherry vinegar or cider vinegar
- Preheat oven to 450 degrees F.
- Mix breadcrumbs, 1/2 teaspoon oil, 1/2 teaspoon rosemary, 1/2 teaspoon salt and 1/8 teaspoon pepper in a small bowl.
- Heat the remaining 1 teaspoon oil in a large ovenproof skillet over medium-high heat. Add lamb, meat-side down, and sear until browned, about 1 1/2 minutes. Turn it over and spread 2 teaspoons mustard over the meat. Sprinkle the breadcrumb mixture over the mustard. Transfer the lamb to the oven and roast until a thermometer inserted in the center registers 140 degrees F for medium-rare, 15 to 20 minutes. Transfer to a plate and tent with foil to keep warm.
- Return the pan to medium-high heat (be careful: the handle will still be hot). Add shallots, the remaining 1/2 teaspoon rosemary, 1/4 teaspoon salt and 1/8 teaspoon pepper and cook, stirring constantly, until starting to soften, about 1 minute. Stir in lentils, apple, celery, broth (or water), vinegar and the remaining 1 teaspoon mustard; bring to a lively simmer. Cook, stirring occasionally, until the liquid is slightly reduced and the celery and apple are starting to soften, about 4 minutes. Cut the lamb into 8 chops and serve over the lentils.