Pierce the spaghetti squash with a knife to allow steam to escape and microwave it until tender, about 8-12 minutes. Alternatively, roast it in the oven until soft. Let it cool completely to handle safely.

Season the bite-sized chicken pieces with salt, pepper, and Italian seasoning. Melt 1 tablespoon of butter in a skillet over medium-high heat. Add chicken and cook thoroughly until no longer pink inside. Remove and set aside.

In the same skillet, add remaining tablespoon of butter. Add minced garlic and shallot, cooking until softened and fragrant. Stir in the julienned sun-dried tomatoes.

Pour the heavy cream into the skillet and bring it to a gentle bubble. Turn off the heat and stir in the grated Parmesan cheese and baby spinach until wilted. Return the cooked chicken and mix well.

Carefully cut the cooled spaghetti squash in half lengthwise, remove seeds, and shred the flesh into spaghetti-like strands using a fork.

Stir the shredded spaghetti squash into the creamy chicken sauce until well incorporated. Garnish with fresh parsley if desired, and serve hot.