Step 1Combine the garlic, rosemary, wine and salt in a food processor and puree to form a thin paste.
Step 2Pat the roast dry with a paper towel and carefully score the skin into diamond shapes. This is most easily done with a small sharp knife. Place the roast in a 2-gallon resealable plastic bag along with the garlic-rosemary paste. Press out all of the air and seal tightly. Massage the leg, spreading the paste over the entire surface. Refrigerate overnight, turning the leg and rubbing it occasionally to spread the paste as thoroughly as possible.
Step 3The next day, remove the leg from the bag and place it upright on plate, with the shank pointing straight up. Refrigerate, uncovered, for at least 2 hours.
Step 4Cook according to the master recipe.