The day before cooking, trim excess fat from roast.
Clean and thinly slice the garlic. Insert at about 2 inch intervals with a sharp knife into the roast, about 1/2″ deep.
With a meat injector, inject apple juice into the roast at various intervals in top, sides and bottom.
Rub the roast with olive oil and sprinkle with pepper, oregano and salt. Place the roast on a large sheet of plastic wrap and wrap tightly after seasoning. Place in a plate or pan and refrigerate overnight.
The next day, remove the roast from the refrigerator at least 2 hours before cooking so that it is room temperature before placing in the oven.
Heat the oven to 500 degrees. Unwrap the roast and place on a rack in a large roasting pan. Place oven rack at lowest position. Cook roast for 5 minutes per pound, no more! Turn off oven (gas ovens, turn on low) and leave roast in oven with door closed for 2 hours. Do not open the oven door at all during this time.
After 2 hours, remove roast from oven and let stand for 20 minutes. Slice and serve.