Carefully slice the spaghetti squash in half lengthwise and scoop out the seeds using a spoon.
Drizzle olive oil on the cut sides of the squash, then sprinkle with salt and pepper.
Place the squash halves cut-side down on a baking sheet and roast in the oven for about 30-40 minutes, or until the flesh is tender and easily shreds with a fork.
While the squash is roasting, prepare the Alfredo sauce: In a saucepan over medium heat, add the minced garlic and sauté for about 1 minute until fragrant.
Pour in the heavy cream, and bring to a gentle simmer, stirring constantly.
Gradually whisk in the grated Parmesan cheese until melted and smooth. Then add Italian seasoning, nutmeg, and season with salt and pepper to taste.
Once the spaghetti squash is cooked, use a fork to shred the flesh into strands and transfer to a large bowl.
Add the shredded chicken and Alfredo sauce to the bowl with the spaghetti squash, and gently mix until well combined.
Serve in bowls and garnish with freshly chopped parsley.
Notes
Feel free to add more vegetables or adjust seasonings to taste.