Preheat your oven to 400 degrees f and grease a 2 quart casserole dish with a bit of avocado oil.
Heat ghee in a large skillet over medium-high heat. Add sausage and mix well breaking apart with a wooden spoon until it's crumbly. Cook until browned, about 5-7 minutes. Once nicely browned, set aside, reserving the grease in the pan.
Using that same skillet, add in oil and reduce to medium heat, then add in onion, celery and garlic. Sauté for about 4 minutes until fragrant and lightly caramelized.
Next, stir in your cauliflower rice, and continue to cook, stirring occasionally for about 5 minutes.
Return the browned sausage to the skillet, and add in your chopped apples, walnuts and thyme leaves; season with sea salt and pepper to your taste, and toss everything well to combine.
Remove from the heat and place your mixture into the prepared casserole dish, cover the top with parchment paper or with aluminum foil (loosely so it doesn't touch the food) and bake in your 400 degree oven for about 15 minutes until golden brown.
Garnish with chopped parsley on top and serve.
Enjoy!