Pierce the spaghetti squash several times with a knife. Microwave on high for 8-12 minutes until tender. Let cool.
Season chicken pieces with salt, pepper, and Italian seasoning.
In a large skillet, melt 1 tablespoon butter over medium-high heat. Cook the seasoned chicken for about 7 minutes until no longer pink; remove and keep warm.
Add remaining butter to the skillet along with minced garlic and shallot; sauté for 1-2 minutes.
Stir in sun-dried tomatoes, then pour in heavy cream; cook until hot.
Reduce heat, mix in Parmesan cheese and spinach; return chicken to pan.
Once cool enough to handle, cut spaghetti squash in half lengthwise, remove seeds, and scrape out strands with a fork.
Combine spaghetti squash with the creamy sauce until well coated; serve garnished with parsley if desired.
