Campfire Garlic Fries

Heat coals over campfire, or preheat grill to medium-high. Tear aluminum foil to make 4 large rectangles. On each foil piece, spread out about 1/4 of the fries. Drizzle each serving with olive oil and toss with salt and pepper. Fold each foil piece in half crosswise and seal the edges to make packets. When the coals (or grill) are hot, add the foil packets. Cook (tossing occasionally to avoid burning) until heated through and golden, about 20 minutes. Open packets and add garlic to each. Toss and let the fries crisp over coals, uncovered, about 1 minute more. Top each serving with cheese and cook until cheese is melty. Remove from coals (or grill). Garnish each serving with scallions.