Place remaining coconut oil in the skillet with the onion, celery, and garlic. Saute for 4-5 minutes, then add in butternut squash. Cook for 8-10 minutes, or until squash is softened. Add in cauliflower rice, broth, rosemary, and sage. Stir and cook for 5-6 minutes, or until cauliflower is softened. Stir in ground pork and transfer to the casserole dish. Bake for 20 minutes, or until cooked throughout and slightly crisp on top. Top with chopped nuts if desired and enjoy!