1 (14 to 15-pound) turkey, neck and giblets reserved
1 orange, cut into wedges
1 lemon, cut into wedges
1 onion, cut into wedges
6 fresh rosemary sprigs
6 fresh sage sprigs
6 fresh oregano sprigs
7 tablespoons unsalted butter
2 tablespoons herbes de Provence
1 tablespoon olive oil
1 1/2 teaspoons salt
1 1/2 teaspoons freshly ground black pepper
6 cups canned low-salt chicken broth (approximate amount)
1/3 cup all-purpose flour