1. Combine the melted butter, salt, pepper. Remove the seeds from the squash, and brush over the cavity of squash.
2. Bake in a large roasting pan, cut side up, at 400 degrees F for 45 minutes to 1 hour, until squash is tender yet still holds its shape.
3. Combine the stuffing, vegetables, cranberry relish, and turkey in a large bowl. Taste and season with sage, thyme, rosemary, salt and pepper as desired. Add in nuts if using.
5. Fill the squash halves with stuffing. Fill them up a good amount and in a moulded shape.
6. Return to oven and bake, uncovered, for 10 more minutes.
7. Serve hot!