Trim fat from meat. With the tip of a knife, cut 1/2-inch-wide slits into roast at 1-inch intervals (approximately 36 holes), inserting a thin slice of garlic into each. Brush meat surface with lemon juice. Stir together parsley, oil, Italian seasoning or oregano, and pepper. Pat parsley mixture onto meat . Wrap tightly in plastic wrap, refrigerate overnight.

Place meat, fat side up, on a rack in a shallow roasting pan. Insert a meat thermometer into center of meat, without touching bone. Roast in a 325 degrees F oven until thermometer registers 140 degrees F for medium rare (1 3/4 to 2 1/4 hours) or 155 degrees F for medium (2 to 2 1/2 hours). Transfer meat to serving platter. Cover meat with foil and let stand for 15 minutes before carving. (The meat's temperature will rise 5 degrees F during standing.) Makes 12 to 16 servings.

To use 2, 1 1/2- to 2-pound boneless leg roast: Prepare as above except roast 1 to 1 1/4 hours for medium rare or 1 1/4 to 1 1/2 hours for medium.