Preheat oven to 400˚. Line a roasting pan with foil, and place a wire rack on top; spray rack with cooking spray.
Sprinkle lamb with salt and pepper. In a large skillet, heat 1 tablespoon olive oil over medium-high heat. Add lamb, and cook until browned, about 3 minutes per side. Transfer lamb to roasting pan, and place, fatty side up, on rack.
In a small bowl, stir together mustard, shallot, and garlic. Rub over lamb.
In a separate small bowl, stir together bread crumbs, rosemary, thyme, mint, lemon zest, and remaining 3 tablespoons oil. Press bread crumb mixture over mustard mixture on lamb.
Bake until a thermometer inserted in thickest portion of lamb registers 130˚, about 20 minutes. Loosely cover with foil, and let stand for 10 minutes before slicing.
Notes
*Ask your butcher to french the lamb, or follow our method for giving the rack a neat and elegant appearance: With the lamb on the cutting board with bones facing up, score the membrane by placing the tip of a sharp knife against the center of each bone, starting about an inch and a half from the cut end of the bone and pulling the knife slowly and firmly down the bone to cut end. Using a dish towel, pull fat and membrane from between each rib slowly and firmly. It should pull away cleanly. Continue working flesh away from the bones until about 2 inches are exposed. Turn the rack over, and cut away fat and membrane. Scrape away any remaining connective tissue and meat to clean the bones.
Recipe by Victoria at https://victoriamag.com/herb-crusted-rack-lamb-recipe/