Spray a large saucepan or soup pot with nonstick cooking spray. Add the onion, carrot and celery and cook over low heat, stirring often until the vegetables have softened.
Add the garlic and stir for another minute.
Add the broth, tomatoes, cabbage, spinach, tomato paste, basil, thyme and salt and bring to a boil over medium high heat. Lower the heat, cover the pot and simmer gently for about 15 minutes.
Add the zucchini and cook until softened, 3 - 5 minutes more.
Stir in chopped fresh parsley or basil just before serving if desired.
Slow Cooker Instructions: Place everything in your slow cooker,, cover and cook on LOW until tender, 6 to 8 hours).
Use whatever combination of low starch vegetables you like best.
For a thicker soup, puree a portion of this soup and then add it back into the pot.
Stir in some fresh chopped parsley or basil an added burst of freshness.Note:
Top with chopped parsley or basil for garnish (optional).