How to Make It
In a heatproof bowl, soak the porcini in the boiling water until softened, about 20 minutes. Rub them to loosen any grit and coarsely chop. Let the soaking liquid stand for 5 minutes, then pour it into a bowl, leaving any grit behind.
Heat 2 tablespoons of the oil in an enameled cast-iron casserole. Add the drumsticks, season with salt and brown on all sides over moderately high heat, about 10 minutes. Transfer to a plate. Add the carrots and onion to the casserole, season with salt and cook, stirring, until lightly browned, 8 to 10 minutes.
Return the drumsticks to the pan. Add the wine, porcini and their soaking liquid, thyme and bay leaves and bring to a boil. Cover and simmer over low heat until the turkey is falling off the bones, about 3 hours; turn them 2 or 3 times during cooking. Discard the thyme and bay leaves.
Heat the remaining 2 tablespoons of oil in a medium skillet. Add the scallions, season with salt and cook over moderately high heat until softened and lightly browned, 3 to 5 minutes. Transfer the scallions to a plate. Add the Portobellos to the skillet, season with salt and cook over high heat, turning them once, until softened and golden, 5 to 8 minutes.
Cut the turkey meat off the bone into large pieces, and discard the sticklike tendons. Boil the cooking liquid until it lightly coats a spoon, 10 to 15 minutes. Add the Portobellos; season with pepper.
Put the turkey into soup plates and spoon the Portobellos and sauce on top. Arrange the scallions alongside and serve.