Preheat oven to 400 degrees F. Cut spaghetti squash in half, lengthwise, and remove the excess seeds and strings. Place open side down on a baking sheet and cook for 20-25 minutes or until spaghetti squash is soft when you push the skin or the threads easily come out when you take a fork to it. Once the squash is in the oven, dice onion and artichokes.
Place skillet over medium heat, add butter, diced onions and artichokes. Cook until onions are translucent, about 5 minutes. Remove from heat and cool. In a large bowl, mix together ground turkey, artichokes, onions and rest of the ingredients. Mix well. Roll into meatballs, about 1 inch in diameter (makes about 18).
Place on a baking sheet lined with parchment paper. Bake for about 15 minutes. Place tomato sauce on the cook top in a saucepan to warm, add chopped spinach and simmer until food is ready. Place spaghetti squash serving on a plate and top with meatballs and tomato sauce. Enjoy!