Pollo al Mattone (Chicken Under a Brick)

Rinse chickens inside and out under cold running water. Pat dry with paper towel. Place the chickens, breast-side down, on a clean work surface. Use kitchen scissors or poultry shears to cut along either side of backbones and discard. Turn chickens over and push down to flatten. Tuck wings under. Transfer to a large glass or ceramic dish. Combine the oil, rosemary and garlic in a bowl. Season with pepper. Pour the oil mixture over chickens. Turn to coat. Cover with plastic wrap and place in the fridge for 4 hours or overnight to marinate.

Preheat oven to 200ºC. Preheat a large roasting pan in oven for 10 minutes. Season the chickens with salt and place, breast-side down, in the prepared pan. Top with another large roasting pan and top with 2 bricks to weigh it down. Roast for 20 minutes. Remove bricks and pan. Turn the chickens. Replace pan and bricks. Roast for 20 minutes. Remove the bricks and pan. Turn the chickens and roast, uncovered, for a further 20-30 minutes or until the chickens are golden and cooked through. Cut into serving pieces and transfer to a serving platter. Drizzle over the juices from the roasting pan.