Remove the backbone from a whole bird and it will lie flat, instantly doubling the surface area—and the flavor and crisping potential. I almost always do chicken like this now, and it’s also perfect for turkey and small birds like pheasants and guinea hens. Figure a 3- to 3 1 ⁄ 2-pound pheasant will take about an hour; a 10- to 14-pound turkey will take…