Preheat oven to 400°F and grease large casserole dish.
Cut the spaghetti squash in half* and lay face down on a lined baking sheet. Bake for approximately 30 minutes or until tender. Remove from oven and let them cool enough to be handled. Scoop out the seeds and then using a fork scrape out the rest of the stringy squash and place it in a large mixing bowl.
While the squash is baking cook your bacon in a medium skillet over medium heat. Set aside to cool and then chop into small pieces.
Using the leftover bacon grease or another fat of choice (like 2 tbs olive oil), sautee the chopped shallot and garlic.
In a medium pot, add water and cauliflower. Bring to a boil and cook for 5-10 minutes or until cauliflower can be pierced with a fork. Remove from heat and the nutmeg, salt and pepper. Using a hand blender or transfer everything to a food processor/blender, blend the cauliflower mixture until well combined and everything is in a liquid sauce state. It will be slightly gritty due to the cauliflower.
In the large mixing bowl add the cauliflower sauce, garlic, shallot, garlic powder, crushed red pepper, shredded chicken, spinach, diced onion, chopped artichoke and the chopped bacon to the spaghetti squash and mix until well combined. You can also add more salt and pepper here.
Pour into greased casserole dish and bake for 1 hour.