Creating Garlic Parmesan Stuffed Spaghetti Squash with Chicken & Spinach can be easy if you follow these meticulous steps:

1. Preheat your oven: Set the temperature to 400°F (200°C).

2. Prepare the Spaghetti Squash: Cut the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the inside with olive oil and sprinkle with salt and pepper.

3. Roast the Squash: Place the squash halves cut side down on a baking sheet. Roast in the preheated oven for 30-35 minutes or until tender.

4. Cook the Chicken: While the squash is roasting, heat olive oil in a skillet over medium heat. Add diced chicken and season with salt, pepper, and Italian seasoning. Cook until the chicken is browned and cooked through, about 7-10 minutes. Remove from heat.

5. Sauté the Spinach: In the same skillet, add minced garlic and sauté for 1-2 minutes until fragrant. Add chopped spinach and cook until wilted, about 2-3 minutes. Combine the spinach and garlic mixture with the cooked chicken.

6. Mix in Cheeses: Remove the skillet from heat, then stir in grated parmesan cheese and half of the mozzarella cheese into the chicken and spinach mixture, mixing until well combined.

7. Stuff the Squash: Once the spaghetti squash is cool enough to handle, use a fork to scrape the flesh into strands. Combine the squash strands with the chicken, spinach, and cheese mixture. Fill the spaghetti squash halves with the chicken and cheese mixture.

8. Top with Mozzarella: Sprinkle the remaining mozzarella cheese on top of the stuffed spaghetti squash.

9. Bake Again: Return the stuffed squash to the oven and bake for an additional 10-15 minutes, until the cheese is melted and bubbly.

10. Garnish and Serve: Remove the squash from the oven and let it cool slightly. Garnish with fresh parsley before serving.

Following these steps will lead you to a beautifully crafted dish that represents a fantastic balance between flavor and nutrition.