Using a sharp knife, carefully cut out a circle on top of the pumpkin(s) making a lid as you would to carve a Jack O' Lantern. Remove the seeds and any loose strings, then generously sprinkle salt and pepper inside the pumpkins. Place the pumpkins on baking sheet lined with parchment paper.
Heat ghee or coconut oil in a large pan over medium-high heat.
Add diced onions and garlic to the pan, sprinkle with salt and pepper, and sauté until soft and translucent.
Add the sausage and brown, stirring occasionally and breaking it into crumbles with a wooden spoon, about 8 minutes.
Transfer to a large mixing bowl.
Add carrots, celery, cranberries, chicken broth, and balsamic vinegar to the pan, sprinkle with salt and pepper, and simmer until the liquid is evaporate, about 8 minutes.
Transfer the vegetables in the bowl with onions and sausage. Let the mixture cool for 10 minutes, then add chopped walnuts.
Whisk together eggs, thyme, sage, salt, and pepper, then pour over the stuffing mixture. Stir well.
Transfer the stuffing into the pumpkin(s), filling up to the top.**
Place the lid on top of the pumpkin(s), and transfer to the oven.
Bake until the pumpkin skin is soft, about 45 minutes - 2 hours depending on the size of your pumpkin.
**If there is leftover stuffing, bake in a small dish with the pumpkins covered with aluminum foil.