Snip 2 tablespoons each of the parsley and cilantro. In a small bowl combine snipped parsley and cilantro, 1 tablespoon of the oil, and one-third of the garlic; set aside.
Trim fat from meat. To butterfly pork, make a lengthwise cut down the center of the meat, cutting to within ½ inch of the opposite side. Spread meat open. Starting at the center, make one horizontal slit to the right and one horizontal slit to the left. Spread meat open.
Brush meat with the remaining 2 tablespoons oil. Sprinkle with the remaining parsley and cilantro leaves, the remaining garlic, lime peel, and the ¼ teaspoon pepper. Starting at a short edge, roll up meat. To secure, tie roll at 2-inch intervals with 100-percent-cotton kitchen string. Spread the reserved snipped herb mixture over outside of meat and sprinkle with additional pepper.
For a charcoal grill, arrange medium-hot coals around a drip pan. Test for medium heat above pan. Place meat on grill rack over drip pan. Cover and grill for 45 minutes to 1 hour or until an instant-read thermometer inserted in meat registers 145 to 150°F. (For a gas grill, preheat grill. Reduce heat to medium. Adjust for indirect cooking. Grill as above.)
Remove meat from grill. Cover with foil; let stand for 3 minutes before slicing. If desired, let stand for 15 minutes; the meat's temperature will rise 10°F during this standing.
Meanwhile, place pineapple on the grill rack directly over coals. Grill for 5 to 10 minutes or until pineapple is warm and shows grill marks, turning once halfway through grilling. Remove and discard string from meat. Slice meat. Serve with grilled pineapple.