To cook a rack of lamb, rub the lamb with rosemary, salt, pepper and garlic at least one hour before cooking, and roast the lamb at 425 degrees Fahrenheit until it reaches an internal temperature of 145 degrees. Allow the lamb to rest before slicing and serving it.
At least one hour before cooking, rub two 1 1/2 pound racks of lamb with a combination of 2 teaspoons of kosher salt, 1/2 teaspoon of black pepper, one minced garlic clove and 2/3 cup of fresh, chopped rosemary leaves, then cover the prepared meat with plastic wrap. Allow the lamb to reach room temperature before cooking, but do not allow the meat to remain unrefrigerated for longer than two hours.
To cook the lamb, preheat the oven to 425 degrees Fahrenheit, and place the roasting pan inside the oven for 10 minutes. Pat the lamb with paper towels to remove excess moisture, and drizzle the meat with 2 teaspoons of olive oil. Place the lamb in the hot roasting pan with the bones on the top, and roast the meat for 15 to 20 minutes, or until the lamb reaches an internal temperature of 145 degrees Fahrenheit. Allow the lamb to rest for 10 minutes after removing it from the oven before slicing.