Many rack of lamb recipes call for "frenched" lamb. This means removing the cartilage and fat between the rib bones so the clean bones are exposed. You can ask your butcher to do this for you, or you can try the technique yourself. Just use a small, sharp knife to cut away the cartilage and fat, and if necessary, scrape the exposed bone clean.
It's surprisingly easy to make tender, juicy lamb that's ready to fall off the bone. This lamb recipe is perfectly simple, with just a few steps to follow.
Process salt, rosemary, and garlic in a food processor until they are as finely minced as possible. Then, add mustard and balsamic vinegar and process for 1 minute.
Place the lamb in a roasting pan with the ribs curving down. Coat the top of the meat with the mustard marinade, and allow to stand at room temperature for 1 hour.
Preheat oven to 450 degrees F. Roast lamb for exactly 20 minutes for rare or 25 minutes for medium-rare. Remove lamb from the oven and cover with aluminum foil. Allow lamb to sit for 15 minutes. Then cut the rack into individual ribs and serve.