Preheat oven to 200°c/180° fan forced.
Rub lamb racks with garlic and place in a roasting pan. Bake for 10 minutes.
Meanwhile, combine cheese, mustard, worcestershire sauce, parsley and pepper to taste; spread over lamb. Cook for a further 15 minutes or until cooked to your liking.
Prepare Gravy Mix following packet directions. Whisk in extra mustard.
Slice lamb and serve with gravy and vegetables of your choice.