Preheat the oven to 450ºF (with convection, if you've got it). Cut potatoes lengthwise and then lay them flat to chop them down to french fry size.
Line two baking sheets with parchment paper and divide fries between them. Toss with oil and salt. Bake for 20 minutes, flipping once, or until golden and crispy. Once the fries are done, sprinkle them with the cheese and return to the oven until it starts to melt, about 2 minutes.
Meanwhile, reheat the turkey and gravy. (You can reheat them together in one pot if you like).
Top the fries with the turkey and gravy and serve with cranberry sauce.