In a mortar and pestle or spice grinder, grind together salt, bay leaf, thyme, and peppercorns. Mash in garlic. Pat roast dry with paper towels. Rub olive oil all over roast, then rub spice mixture evenly over roast. Cover and refrigerate overnight, turning pork occasionally.
Heat oven to 350º F. Place rack in roasting pan. Place pork in a roasting rack and roast until internal temperature is 150 degrees, about 1 hour 25 minutes. Tent with foil and let rest 20 minutes before slicing.