Preheat oven to 375. Spray a casserole pan with oil and set aside.
Microwave spaghetti squash until soft (about 7 min). Poke holes in it so it doesn’t explode! Once soft, cut in half, remove the seeds in the center, and shred strands. Set aside.
Add EVOO and ghee to a medium-large skillet on medium heat and saute mushrooms until cooked. Add a dash of Himalayan sea salt, mix, and set aside.
Make cheese sauce by microwaving cauliflower rice in a microwave for approx 4.5 to 5 min or until soft (drain excess water if necessary). Place cauliflower rice and remaining ingredients in a medium sauce pan over low-medium heat until cheese has melted. Stir. Use an immersion blender or blender to blend sauce until a smooth and creamy consistency is achieved. Taste to make sure you're happy with the amount of salt and pepper added.
Crack egg and egg whites into a small bowl and whisk.
Add spaghetti squash, mushrooms, and cheese sauce together in a large bowl and mix. Add eggs and mix. Pour into a casserole dish. Top with shredded parmesan cheese, if desired.
Bake casserole for 1 hour, or until brown on the top and egg is cooked through.