Remove excess fat and all skin from pork roast. Pierce meat in several areas and marinate roast in a mixture of garlic, salt, juice, pepper, bay leaves, oregano, cumin, and olive oil for at least 1 hour. Place roast in a pan with the fat side up, and reserve marinade for bating. Roast at 350 F for about 2 1/2 hours or until a meat thermometer registers 170 F and the meat is browned. Turn the meat and baste frequently with marinade while cooking. If drippings begin to smoke or burn, add a little water to the drippings in the pan. After meat is well done, remove from oven allow to cool before cutting into thick slices. Serve with Mojo, black beans, white rice, and fried sweet or green plaintains (tostones de plátano verde).